Compositions, methods and devices for maintaining an organ

ABSTRACT

Compositions, methods, systems/devices and media are provided for maintaining a harvested organ in a functioning and viable state prior to implantation. The organ perfusion apparatus includes a preservation chamber for storing the organ during the preservation period. A perfusion circuit is provided having a first line for providing an oxygenated fluid to the organ, and a second line for carrying depleted fluid away from the organ. The perfusion apparatus also includes a device operably associated with the perfusion circuit for maintaining the organ at a substantially normothermic temperature.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.11/060,906, filed on Feb. 17, 2005, which is a continuation of U.S.application Ser. No. 09/534,092, filed on Mar. 23, 2000, which is acontinuation of PCT/US98/19912, filed on Sep. 23, 1998, which is acontinuation-in-part of U.S. application Ser. No. 09/054,698 filed onApr. 3, 1998, which is a continuation-in-part of U.S. application Ser.No. 08/936,062 filed on Sep. 23, 1997. The specifications of each of theabove applications are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to compositions, methods, systems/devicesand media for maintaining a harvested (extracorporeal) animal organ in afunctioning and viable state prior to transplantation or reimplantation.In particular, the present invention relates to compositions, methods,systems/devices and media for maintaining a harvested human orhuman-compatible organ in a functioning an viable state. The organ mayalso be assessed in such state or resuscitated after death.

The present invention also relates to an organ perfusion apparatus, andmore particularly, to a perfusion apparatus and method and chemicalcompositions for extending the preservation period of an organ which hasbeen harvested.

2. Discussion

While having many embodiments, the present invention is directed tosystems, devices (apparatuses), methods and media for preserving organsin near ideal conditions and physiological states. This allows theorgans to be stored for longer periods of time, reduces degradation ofhigh energy phosphates during storage, reduces ischemia and reperfusioninjury, and overall improves outcome. The increase in storage periods ina normal or near normal functioning state also provides certainadvantages, for example, organs can be transported greater distances andthere is an increased time for testing and evaluation of the organs.

It is estimated that one of every four patients listed for cardiactransplantation dies awaiting the availability of a suitable donatedorgan. While some progress has been made in making more donor organsavailable, the development of successful techniques for donor heartpreservation has not kept pace with the demand for cardiactransplantation. With improvements in patient survival and thedevelopment of new immunosuppressive agents, heart transplantation hasbecome more feasible, making the problem of organ supply even morecritical. Despite the acceptable clinical results obtained with thecurrent donor organ and donor heart preservation techniques, one of themajor challenges that remains is the current inability to safelypreserve the donor heart for more than four hours. Extending thepreservation period beyond four hours using current preservationtechniques significantly increases the risk of organ failure during orafter transplantation; this failure correlates with the period andtechnique of storage. This four hour limitation also restricts thegeographic area from which donor hearts can be transported forsuccessful transplantation. Moreover, current methods of storing orpreserving the heart or other organs make it impossible to fully ormeaningfully test or evaluate the stored organ due to the storage of theorgan in a non-functioning and/or hypothermic state.

Generally, current donor organ preservation protocols do not attempt torecreate an in vivo-like physiologic state for harvested organs.Instead, they utilize hypothermic (below 20° C. and typically at about4° C.) arrest and storage in a chemical perfusate for maintaining theheart (non-beating) or other organ (non-functioning) for up to fourhours. These protocols utilize a variety of crystalloid-basedcardioplegic solutions that do not completely protect the donor heartfrom myocardial damage resulting from ischemia and reperfusion injuries.The most common cardioplegic preservation solutions used are TheUniversity of Wisconsin Solution (UW), St. Thomas Solution, and theStanford University Solution (SU). In addition to myocardial damage,ischemia, reperfusion and/or increased potassium concentrations may alsocause coronary vascular endothelial and smooth muscle injury leading tocoronary vasomotor dysfunction, which is believed to be the leadingcause of late organ failure. (Ischemia is generally defined as aninsufficient blood supply to the heart muscle.)

Techniques have also been developed for perfusing the heart with thestorage solution in the hypothermic state. Other organs (liver, kidney,lungs, etc.) have been maintained in a similar, non-functioning,hypothermic state. The heart or the other organs so preserved are thentransported in this hypothermic state for only up to four hours untilimplantation.

As is well known in the art, for optimal donor heart or other organpreservation, the following principles apply and are thought to assistin the minimization of ischemic and/or reperfusion injuries: a)minimization of cell swelling and edema; b) prevention of intracellularacidosis; c) minimization of ischemia and/or reperfusion injury; and d)provision of substrate for regeneration of high-energy phosphatecompounds and ATP during reperfusion. The current methods of hypothermicarrest and storage preservation have been shown to result in cellswelling, intracellular acidosis, and a degradation of high-energyphosphates. Moreover, studies in humans have clearly demonstratedsignificant endothelial dysfunction following donor heart preservationwhen utilizing hypothermic arrest and storage protocols. In someinstances, an organ which has undergone hypothermic arrest istransplanted into the recipient and cannot be restarted or resuscitatedafter transplantation. In addition, many times inadequate preservationresults in acute graft failure and the inability of the transplantedorgan to resume normal function and sustain the recipient's circulation.The problem of acute graft failure then requires constant support of therecipient's circulatory system by ventricular assist devices and/orcardiopulmonary bypass until another donor heart can be located. In someinstances, a suitable organ cannot be located in time which results inthe death of the recipient. There is also increasing evidence from anumber of recent clinical studies that the preservation of metabolic,contractile and vasomotor function is not optimized with currentpreservation protocols. See, e.g., Pearl et al., “Loss ofEndothelium-Dependent Vasodilatation and Nitric Oxide Release AfterMyocardial Protection With University of Wisconsin Solution”, Journal ofThoracic and Cardiovascular Surgery, Vol. 107, No. 1, January 1994.

Because the art has not been able to store harvested organs at nearoptimal endogenous conditions, and has not recognized such storage asfeasible or desirable, it has attempted to use the above combination ofhypothermic conditions and/or crystalloid-based cardioplegic solutionsfor protection against organ condition deterioration.

Another approach attempted in the art has been to simulate near normalphysiologic conditions by harvesting almost all the donor's organstogether. For example, Chien et al., “Canine Lung Transplantation AfterMore Than Twenty-four Hours of Normothermic Preservation, The Journal ofHeart and Lung Transplantation, Vol. 16, No. 3, March 1997, developed anautoperfusion set-up in which a swine heart was preserved in a beating,working state for up to 24 hours by being continuously perfused withnon-compatible blood. While this system demonstrated the feasibility ofsafely extending the preservation time of the donor heart, this methodis far too cumbersome and impractical for widespread use as it requiresthe removal and preservation of the lungs, liver, pancreas, and kidneys(en bloc) in combination with the heart, all in functioning condition,and all still interacting and interdependent.

There is a need in the art to achieve prolonged ex vivo orextracorporeal preservation of the donor heart or other organ that hasbeen harvested from a donor by providing continuous sanguineousperfusion, while maintaining the donor heart or other organ in thenormal (beating or functioning) state. Such a technique would eliminatethe need to arrest the heart for storage in a hypothermic environment,reduce reperfusion injuries, and overcome many of the problemsassociated with hypothermic arrest and storage, many of which areclearly time dependent.

There is a further need in the art to provide an apparatus, method andphysiologic media for creating an extracorporeal circuit forsanguineously perfusing the harvested organ at normothermic temperatures(about 20° C. to about 37° C.; preferably about 25° C. to about 37° C.)for prolonged preservation of the harvested organ for up to twenty-fourhours or longer. Such an apparatus, method and media would optimallymaintain the heart or other harvested organ in the beating orfunctioning state during the preservation period to insure pulsatilecoronary flow and homogeneous distribution of the substrate. Such anapparatus, system, method and media would provide the ability to extendthe preservation period of the harvested organ beyond the current fourhour limit, while avoiding time dependent ischemic injury and prolongedischemia, thereby preserving coronary endothelial vasomotor function,and preventing the metabolic degradation of high-energy phosphates.

Additionally, such an apparatus, method and media would allow forexpanding the organ donor pool, increasing the histocompatibilitymatching time, and potentially reducing the incidents of cardiacallograft vasculopathy. It will be appreciated that prolonging thepreservation period of the donor heart would have a dramatic impact onthe practice of heart transplantation; a worldwide retrieval of organswould be made possible, thus increasing the pool of available organs.Organs would not go unused because of lack of suitable nearbyrecipients. Moreover, additional time in combination with storage in thefunctional state would allow evaluation and testing of the organ todetermine, e.g., the immunologic and functional characteristics of eachorgan, thereby allowing a more complete assessment of the organ,reducing the risk of graft failure.

In summary, the prior art has failed to appreciate the feasibilityand/or desirability of employing a near ideal physiologic state ex vivofor harvested organs.

This state is provided for by the compositions, methods andsystems/devices of the present invention. A fluid or fluid media isprovided comprising (1) donor-compatible whole blood (orleukocyte-depleted whole blood) and (2) a storage solution whichincludes a carbohydrate source, insulin and other hormones includingepinephrin, electrolytes and a buffer such as a source of bicarbonateions. This fluid or fluid media is delivered to at least one majorvessel and optimally to the “exterior” portions of the organsubstantially surrounding or bathing the organ. The compositions,methods, systems/devices and media of the present invention can thus beemployed to provide ideal storage conditions at normothermic orsubstantially normothermic temperatures, allowing the organ to remainfunctioning.

SUMMARY OF THE INVENTION

The present invention provides a system for preserving a human orhuman-compatible harvested organ in need of preservation orresuscitation during a preservation or evaluation period prior toimplantation, including transplantation or reimplantation. The system ofthe invention also allows the organ to be transported to alternategeographic locations during the preservation period. This systemincludes:

(a) containment means for containing said organ in communication with aphysiologic media or fluid comprising (i) whole blood (orleukocyte-depleted whole blood) compatible with said organ and (ii) apreservation solution;

(b) delivery means for delivering said fluid to at least one majorvessel of said organ;

(c) means for carrying said fluid away from said organ;

(d) temperature control means for maintaining the temperature of theperfusate and said organ at a normothermic temperature of about 20° C.to about 37° C.;

(e) pressure control means for controlling the pressure of said fluid;

(f) oxygenation means for oxygenating at least a part of said fluid;

(g) filtering means for removing unwanted filtrate from said fluid, saidfiltering means preferably positioned between said oxygenation means andsaid organ; and

(h) flow control means for controlling the flow of at least a part ofsaid fluid.

The system optionally includes means for delivering said fluid to saidcontainment means so that the exterior of said organ is substantiallycompletely bathed in or surrounded by said fluid.

The present invention also provides an organ preservation solution forthe preservation of a human or human-compatible harvested organ in afunctioning state at a normothermic temperature of about 20° C. to about37° C. that is particularly useful in combination with the systems andmethods of the present invention. These solutions include:

(1) a carbohydrate or other energy source;

(2) sodium chloride;

(3) potassium;

(4) calcium;

(5) magnesium;

(6) bicarbonate ion;

(7) epinephrin; and

(8) adenosine.

These solutions may further include a fatty acid as well as apharmaceutical agent selected from nitroglycerin, ACE inhibitors, betablockers, cytoprotective agents, antioxidants, antibiotics,antimicrobials, anti-fungal, anti-viral, immunosuppressives,nonsteroidal anti-inflammatories, steroids, and mixtures thereof.

In a preferred embodiment, the organ preservation solution issubstantially free of nonmetabilizable impermeants; and has a pH ofabout 7.4 to about 8.5.

The present invention also provides a method of preserving a human orhuman-compatible harvested organ in a functioning state during apreservation or evaluation period prior to transplantation orreimplantation. The method includes the steps of:

(a) providing an extracorporeal organ to be preserved or tested;

(b) providing a containment means for said organ;

(c) providing a preservation media or fluid; said fluid mediacomprising:

-   -   (i) whole blood or leukocyte-depleted whole blood that is        compatible with said organ; and    -   (ii) a preservation solution comprising:        -   (a) a metabolizable carbohydrate;        -   (b) sodium chloride;        -   (c) potassium;        -   (d) calcium;        -   (e) magnesium;        -   (f) bicarbonate;        -   (g) epinephrin; and        -   (h) insulin;

(d) delivering the fluid to at least one major vessel of the containedfunctioning organ while the organ is maintained at a normothermictemperature of about 20° C. to about 37° C. In a preferred embodiment,the fluid is also delivered to the exterior of the organ.

The present invention provides systems, apparatuses, methods and mediafor providing optimal and prolonged ex vivo preservation of the donororgan or heart by implementing a method capable of continuoussanguineous perfusion in the normal or near-normal beating orfunctioning state. According to the systems, apparatuses, methods andmedia associated with the present invention, this preservation periodcan be extended for twenty-four hours or more with the heart or otherorgan maintained in a viable state.

Accordingly, by way of example, in one embodiment, a perfusion apparatusfor maintaining a harvested organ during a preservation period isprovided. The perfusion apparatus includes a preservation chamber forstoring the organ during the preservation period. A perfusion circuit isprovided having a first line for providing an oxygenated fluid to theorgan, and a second line for carrying depleted fluid away from theorgan. The perfusion apparatus also includes a device operablyassociated with the perfusion circuit for maintaining the organ at asubstantially normothermic temperature. Moreover, the perfusionapparatus maintains the organ in a viable state.

In another embodiment, by way of example, a method of perfusing an organor donor heart is provided. The method comprises providing apreservation chamber for containing the organ, and a perfusion circuitoperably associated with the preservation chamber. The perfusion circuitincludes a first line for delivering fluid to the organ and a secondline for carrying fluid away from the organ. The method also includesproviding several chemical solutions to the fluid in the perfusioncircuit and perfusing the organ or donor heart with the fluid.

The compositions, methods, systems/devices and media of the presentinvention maintain the donor heart in the beating state during thepreservation period to insure homogeneous distribution of the substrate.Maintaining the heart in the beating state further serves to sustainnormal metabolic, contractile and endothelial vasomotor function beyondthe four hour hypothermic arrest and storage period currently employedfor donor heart preservation.

BRIEF DESCRIPTION OF THE DRAWINGS

The various advantages of the present invention will become apparent toone skilled in the art by reading the following specification andappended claims, and by referencing the following drawings in which:

FIG. 1 is a schematic of the perfusion circuit and the componentsforming the perfusion system according to a preferred embodiment of thepresent invention;

FIG. 2 is a cross-sectional view of the preservation chamber formaintaining the donor heart in the beating state according to apreferred embodiment of the present invention;

FIG. 3 is a top plan view of the cover assembly utilized with thepreservation chamber according to the present invention;

FIG. 4 is a perspective view of the perfusion system installed on amobile cart for facilitating transportation of the harvested organ, alsoaccording to a preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of the preservation circuit utilizing anintegrated container and reservoir according to a preferred embodimentof the present invention;

FIG. 6 is a schematic diagram of the preservation circuit in analternate configuration and is shown utilizing a pulsatile pump formaintaining a heart in the non-working beating state according to analternate embodiment of the present invention;

FIG. 7 is a schematic diagram of the preservation system and soft shellcontainer for maintaining a kidney according to the teachings of thepresent invention;

FIG. 8 is a schematic diagram of the preservation system and soft shellcontainer for maintaining a liver according to the teachings of thepresent invention;

FIG. 9 is a schematic diagram of the preservation system and soft shellcontainer for maintaining a pancreas according to the teachings of thepresent invention;

FIG. 10 is a schematic diagram of the preservation system and soft shellcontainer for maintaining one or two lungs according to the teachings ofthe present invention;

FIG. 11 is a perspective view of the portable preservation system formaintaining any number of organs according to the teachings of thepresent invention;

FIG. 12 is a flow diagram according to the method of the presentinvention.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a perfusion apparatus and methodfor extending the preservation time of at least one human or humancompatible organ, such as a human heart, which has been harvested fortransplantation or reimplantation.

Referring now to FIG. 1, the perfusion system 10 is shown in accordancewith the present invention. While FIG. 1 illustrates a schematic ofperfusion system 10, it will be appreciated that various modificationsto this schematic are within the scope of the present invention. Thepresent invention allows the donor heart to be optionally harvested inthe beating state and connected to perfusion system 10 where the organis maintained in the beating state and provided with a pulsatile,physiologic coronary flow. Accordingly, the donor heart does not have tobe arrested prior to its connection with perfusion system 10. Moreover,since the donor heart is not stored in the arrested hypothermic stateduring the preservation period, time dependent ischemic injury iseliminated. Another advantage of the present invention is that theperfusate used to extend the preservation period is comprised primarilyof autologous (preferred) or in some cases homologous blood which iscirculated through the perfusion system 10. Thus, the donor heart isprovided with oxygen and essential nutrients during the preservationperiod which maintains the organ in a viable state. Moreover, cellularwaste is carried away from the organ and filtered out of perfusionsystem 10.

Perfusion system 10 is designed to simulate the human cardiovascularsystem for maintaining the donor heart 12 in the beating state forperiods up to or exceeding 24 hours. As with the human cardiovascularsystem, perfusion system 10 comprises a closed perfusion circuit 14 forcirculating a fluid, comprised of autologous blood and other chemicalcompositions, to donor heart 12. Accordingly, perfusion circuit 14includes one or more arterial lines 16 for providing oxygenatedperfusion fluid to donor heart 12, and one or more venous lines 18 forcarrying depleted perfusion fluid away from donor heart 12. As part ofthe method of the present invention, the arterial lines 16 are used forperfusing donor organ 12 in the both the non-working and working states.This method of antegrade perfusion will be discussed in more detailbelow.

With continued reference to FIG. 1, donor heart 12 is shown as beingconnected to perfusion circuit 14. The donor heart 12 is enclosed withina preservation chamber 20 which is preferably made of a hard, clearplastic to allow for visualization of the preserved organ. While it ispreferred that preservation chamber 20 is formed from a plastic materialsuch as LEXANO plastic, the preservation chamber 20 may also be made ofa thick, yet soft flexible plastic in the form of a zipper bag (notshown) to accommodate the contour and shape of donor heart 12. Whenpreservation chamber 20 is a hard plastic container, a plastic coverassembly 22 is used to seal the preservation chamber 20 and to maintainthe sterility and humidity of donor organ 12. When a soft plasticpreservation chamber (not shown) is employed, a zipper is used to sealthe preservation chamber 20 and to protect the organ. A suitable drain24 is provided at the lowest portion of preservation chamber 20. Thedrain 24 is connected to a reservoir 30 via drain line 26 to allow forthe return of any blood escaping from the organ 12 during theinstrumentation period, or from any leakage occurring during thepreservation and transport period.

As disclosed, reservoir 30 is designed to contain approximately 500-3000ml of fluid. Initially, reservoir 30 is primed with 500-2500 ml ofautologous or crossmatched blood which is then pumped throughoutperfusion circuit 14. Alternatively, compatible blood or bloodsubstitute is within the scope of the present invention. The reservoiroutput line 32 is connected to the input of a centrifugal pump 34(preferred) which circulates the perfusion fluid through the arteriallines 16 of perfusion circuit 14. The preferred pump for thisapplication is the Biomedicus 550, manufactured by Medtronic, whichpropels the blood via magnetic field driven cones. While a conventionalroller pump may also be used, the magnetic propulsion generated bycentrifugal pump 34 is preferable to minimize hemolysis of the blood. Ifpulsatile flow is desired, a pulsatile pump such as the HEARTMATE®electric assist pump manufactured by Thermo Cardiosystems Inc., or theNOVACOR left ventricular assist pump manufactured by Baxter HealthcareCorporation, may be employed. An exemplary pulsatile pump is thatdisclosed in U.S. Pat. No. 5,599,173 to Chen et al.

The centrifugal pump 34 propels the blood via pump output line 36 into ahollow fiber membrane oxygenator 38. The blood is oxygenated using apreferred mixture of 95% O2 and 5% CO2 at a rate of 1-2 L/min bymembrane oxygenator 38. The preferred oxygenator is a hollow fibermembrane oxygenator, such as the Monolyth manufactured by SorinBiomedical or the MINIMAX PLUS™ manufactured by Medtronic. While notspecifically shown in FIG. 1, membrane oxygenator 38 is provided withthe oxygen and carbon dioxide mixture through a regulated oxygen bottle178. The oxygenator 38 also includes a plurality of ports (not shown)which allow pressurized perfusion fluid to be directed to other devices.A water heater 40 provides warmed water through a water circuit 42 whichmaintains the fluid within perfusion circuit 14 at about 37° C.(normothermia). The warmed perfusion fluid then maintains donor heart 12at a normothermic temperature. Alternatively, water heater 40 can alsoremove heat from the water circulating through water circuit 42 forcooling the preservation fluid within perfusion circuit 14. Heat can beremoved for a variety of reasons. For example, if the apparatus/system10 is preserving organ 12 in an excessively warm environment (i.e.,exceeding normothermia), heat can be removed from the fluid to preventthe temperature from exceeding 37° C., or another predeterminedtemperature. Heat can also be removed from the fluid in order to coolthe fluid below 37° C. which is desirable when inducing the preservedorgan 12 into a low normothermic and/or mild hypothermic state. This isalso desirable prior to arresting the organ 12. Enough heat may beremoved for lowering the temperature of the fluid and organ down toabout 20° C. The oxygenator output line 44 carries the oxygenated andrewarmed fluid to a filter 46. Preferably, the fluid is filtered with aleukocyte filter, such as the Pall leukocyte-depleting filtermanufactured by Pall Filters.

The output of filter 46 is connected to a selector valve 50 via filteroutput line 48. Selector valve 50 may be placed in one of severalpositions for directing fluid flow to either the initial perfusion line52 (for antegrade perfusion via the aorta), the left atrium supply line54 (for antegrade perfusion via the left atrium), or both linessimultaneously (for priming purposes). Additionally, selector valve 50may be turned off completely. As will be appreciated, lines 48, 54, andat times lines 52 and 58 form the arterial side 16 of perfusion circuit14. The opposite end of the initial perfusion line 52 is connected intoa tee 56 which then branches to aorta line 58 and the afterload column,line 60. A straight connector 61 is used for connecting line 60 with theaorta return line 62. A Luer port 63 having a one-way anti-siphoningvalve secured thereon is secured to connector 61 which acts as a one-wayvalve for allowing fluid pumped across connector 61 to flow throughaorta return line 62 without siphoning additional fluid from afterloadline 60. Luer port 63 operates by allowing air into aorta return line 62for breaking the siphoning effect of the fluid. Accordingly, the peak ofafterload column 60 is formed by connector 61 and Luer port 63.

The distal end of the afterload line 62 is attached to reservoir 30 toallow blood pumped through the aorta 130 to flow back to the reservoir30. As will be discussed in more detail below, aorta line 58 providesbi-directional flow to and from donor heart 12, depending upon whichmode the perfusion system 10 is operating. The height of afterloadcolumn 60 is adjustable between a range of vertical positions forselectively changing the afterload pressure against which the heart 12will beat or pump. Once the fluid pumped through afterload column 60crosses connector 61, it is returned to reservoir 30 via aorta returnline 62. Additionally, a right ventricle return line 64 is connected tothe pulmonary artery 132 to return coronary effluent to the reservoir30. As will be appreciated, lines 58, 60, 62 and 64 form the venous side18 or delivery means of perfusion circuit 14 when the heart is in theworking state.

The aortic flow is measured by an ultrasonic flow probe 66 which is partof aorta line 58. Likewise, an ultrasonic flow probe 68 measures thecoronary blood flow through right ventricle return line 64 of coronaryeffluent from the right ventricle to the reservoir 30. The aortic andcoronary flow signals produced by ultrasonic flow probes 66 and 68 arerecorded on a two-channel flow meter 70 which assists in monitoring thecondition of the preserved organ 12, and the performance of perfusionsystem 10. The preferred flow meter 70 for use with the presentinvention is the two-channel flow meter manufactured by TransonicSystems.

The coronary flow is maintained within acceptable physiologic ranges(300-500 ml/min) by adjusting the height of the afterload column 60above the heart 12 and adjusting the flow rate provided by pump 34. Theafterload pressure is maintained at approximately 70 mm of mercury, butmay be adjusted as necessary. A micro-tip pressure catheter 72 isinserted into the left ventricle via the left atrium 134 for measuringthe intracavitary pressures of donor heart 12. A preferred pressurecatheter 72 is of the type manufactured by Millar Instruments. Allpressure measurements generated by pressure catheter 72 are recorded anddisplayed using a digital pressure recording system 74 which alsoassists in monitoring the condition of the preserved organ 12. Asdisclosed, pressure recording system 74 is capable of recording anddisplaying multiple pressure measurements.

One of the ports from oxygenator 38 is connected to a supply line 76which provides oxygenated blood to a drip manifold 80. As disclosed,three IV bags 82, 84, 86 are connected to drip manifold 80 which providevarious chemical compositions for the preserved organ (discussed in moredetail below). Drip manifold 80 is known in the art and provides amechanism for receiving a regulated drip rate of each chemical solutionstored in the IV bags 82, 84, 86. As is known in the art, the drip ratecan be regulated by an infusion pump (not shown). A manifold output line78 carries the blood, enriched with the various chemical solutions toreservoir 30 for circulation to the donor heart 12.

A variety of materials may be used for creating the various lines andcomponents of perfusion system 10. As almost all of the lines andcomponents of perfusion circuit 14 are in constant contact with theblood perfusate, it is desirable to suppress the acute inflammatoryresponse caused by exposure of the blood to extracorporeal artificialsurfaces. To alleviate this problem, all of the contact surfaces withinperfusion circuit 14 may be coated or bonded with heparin to reducecomplement and granulocyte activation. As an alternative, heparin may bedirectly introduced into the fluid circulating through perfusion circuit14, or other bio-compatible surfaces may be utilized in circuit 14.

With continued reference to FIG. 1, the operation of perfusion system 10will be described in more significant detail. As described above, thedonor heart is harvested in either the beating state or the arrestedstate and placed into preservation chamber 20. At this point,centrifugal pump 34 is propelling oxygenated and rewarmed blood throughline 48. During priming, selector valve 50 is placed into the positionwhich allows blood to flow simultaneously through the initial perfusionline 52 and the left atrium supply line 54. Once the arterial lines 16of perfusion circuit 14 are sufficiently primed to remove the presenceof any air bubbles or air pockets, valve 50 is rotated into the positionfor supplying initial perfusion line 52 with fluid. Aortic line 58 canthen be connected and secured to the aorta 130 using aortic cannula 120.This procedure allows blood to flow to the aortic line 58 for immediateperfusion of donor heart 12 via the aorta 130 in the non-working beatingstate. Optionally, afterload line 60 may be clamped for maximizing bloodflow into the aorta 130. This procedure of antegrade perfusion via theaorta 130 is performed for approximately 10-15 minutes to allow fordonor organ stabilization and to provide a period for instrumentation tobe established. During this instrumentation period, the remaining flowlines are connected to donor heart 12. More specifically, the connectionbetween aorta line 58 and the aorta 130 is completed, supply line 54 isconnected to the left atrium 134, and the right ventricle return line 64is connected to the pulmonary artery 132. The pulmonary veins, superior,and inferior vena cavae are then tied closed using #0 silk suture.During the initial connection protocol, any blood overflow is containedwithin preservation chamber 20 and returned to reservoir 30 via drainline 26.

At the end of the stabilization period, the flow to the aorta 130 isreduced by rotating selector valve 50 to the normal operating positionwhich simultaneously and gradually increases the flow to the left atrium134 via left atrium supply line 54 and gradually shuts off flow throughinitial perfusion line 52. Afterload line 60 is also unclamped. Thisprocedure then switches the donor heart 12 from the non-working stateinto the working state, in which blood is pumped through the venouslines 18 of perfusion circuit 14 by the donor heart 12. It should bespecifically noted that donor heart 12 remains beating at all times.Blood flow to donor heart 12 through arterial lines 16 is assisted bycentrifugal pump 34. The donor heart 12 is allowed to beat against anafterload pressure created by the vertical position of afterload column60 above the preservation chamber 20 thereby generating a pulsatilecoronary flow. Additionally, oxygenated blood is provided to thecoronary vascular system, and de-oxygenated blood from the coronaryvascular system is pumped from the right ventricle into the pulmonaryartery return line 64 and returned to reservoir 30. At this point, donorheart 12 can be maintained in the viable beating state for the durationof the preservation period. While the perfusion system 10 has beenspecifically described for preserving a heart, the apparatus and methodassociated with the present invention is particularly well suited forextending the preservation time for any solid organ by eliminating lines52, 58, 60 and 62, and using line 54 to cannulate the organ's artery,and line 64 to cannulate the vein of the preserved organ. Accordingly,organs including the kidney, liver, lung, pancreas, and small intestinecan be preserved for extended periods of time by perfusion system 10.

Turning now to FIG. 2, the preservation chamber 20 and the connectionsbetween the various cannula and the donor heart 12 are shown in moredetail. As disclosed, preservation chamber 20 has an open top, and isdefined by a generally cylindrical side wall 90 and a sloped bottom 92which promotes the flow of fluid into drain 24 for return to reservoir30 via line 26. Sloped bottom 92 further accommodates the donor organ 12in a more correct anatomical position during the instrumentation andpreservation periods. The top of cylindrical side wall 90 includes anoutwardly protruding flange 94 around its circumference for providing anadditional surface for receiving the cover assembly 22.

Referring now to FIGS. 2 and 3, the components of cover assembly 22 aredescribed in more detail. The outer circumference of cover assembly 22is defined by a clamping ring 96 including two halves which areconnected by a hinge 98. The two halves of clamping ring 96 can berealizably secured via snap lock 100. The remaining portion of the coverassembly 22 is formed by first cover 102 and second cover 104 whichtogether form a circular cover plate having an aperture in the centerthereof for receiving cannula plate 106. Clamping ring 96 has agenerally U-shaped cross-section which is designed for receiving flange94 and first and second covers 102, 104 for creating a tight seal asshown in FIG. 2. The abutting edges 105 between first cover 102 andsecond cover 104 include a tongue-and-groove structure (not shown) forproviding additional rigidity and sealing capability to cover assembly22. In a similar fashion, cannula plate 106 includes an annular tongue108 which fits within an annular groove 110 formed within first cover102 and second cover 104 for securing cannula plate 106 within coverassembly 22. While the tongue-and-groove arrangement associated withabutting edges 105 is not specifically shown, one skilled in the artwill readily appreciate that this arrangement is substantially similarto the arrangement of annular tongue 108 and annular groove 110.

While several variations exist for arranging cover assembly 22, it ispreferred that first cover 102 and second cover 104 are permanentlysecured to the respective side of clamping ring 96. In this fashion, anannular channel 112 remains along the lower inside circumference ofclamping ring 96 for receiving flange 94 when the cover assembly 22 isplaced on top of preservation chamber 20. Upon properly engaging annularchannel 112 with flange 94, both halves of clamping ring 96 can bebrought together for securely fastening snap lock 100 so that the coverassembly 22 may properly maintain the sterility and humidity of theenclosed organ.

Another advantage provided by cover assembly 22 is that cannula plate106 is a separate component which interlocks with first and secondcovers 102, 104 of cover assembly 22 upon installation and securementthereof. As such, the various cannulae secured within cannula plate 106can be attached to the appropriate locations on the organ 12 prior toinstalling cover assembly 22. The cannula plate 106 also positions eachcannula in the proper location while the organ 12 is connected toperfusion system 10. More specifically, cannula plate 106 includes afirst aperture for receiving the aortic cannula 120, a second aperturefor receiving the arterial cannula 122, a third aperture for receivingthe left atrial cannula 124, and a fourth aperture for receiving thepressure catheter 72. Each individual cannula is snapped into cannulaplate 106 to provide a secure connection. It is further contemplatedthat each cannula has a standard sized top tube for snapping into thecannula plate 106, and a variably sized flared lower tube for fittingwithin its associated artery or vein. Therefore, if a cannula with asmaller or larger lower tube is required, it can be swapped into cannulaplate 106 without removing the other cannulae. Accordingly, the designof cannula plate 106 provides a modular component which easily andsecurely integrates with cover assembly 22.

In operation, the fully assembled cannula plate 106 is held in proximityto the beating organ 12 so that aorta 130 can be connected to aorticcannula 120, the pulmonary artery 132 can be connected to the arterialcannula 122, and the left atrial cannula 124 can be properly insertedand secured within the left atrium 134. Preferably, a surgical gradecable tie (not shown) is used to secure the aorta 130 around the aorticcannula 120, and the pulmonary artery 132 around the arterial cannula122. The left atrial cannula 124 is secured within the left atrium 134using size 2-0 prolene surgical suture. As disclosed, the surgical gradecable ties provide a leak-proof seal, and a larger surface area forsecuring the arteries around there cannula without risk of tearing thetissue. This in turn assists in properly supporting donor heart 12within preservation chamber 20. In some instances, as with a smallerdonor heart 12, the heart may be suspended by the aorta 130 withinpreservation chamber 20.

After properly securing the organ to the components of cannula plate 106within preservation chamber 20, each half of 11 d assembly 22 can befitted around the outside circumference of cannula plate 106 so that thecover assembly 22 may be secured on top of the preservation chamber 20.The cover assembly 22 and cannula plate 106 then serve to suspend donorheart 12 within the preservation chamber 20. As best shown in FIG. 2,the pulmonary artery line 64 is secured to the arterial cannula 122, theaorta line 58 is connected to the aortic cannula 120, and the leftatrium supply line 54 is connected to the left atrial cannula 124. Onceall connections have been properly made (approximately 15 minutes), theorgan is allowed to beat for approximately 10-15 minutes in thenon-working state as described above for stabilization. After thestabilization and instrumentation period, the donor heart is thenallowed to beat in the working state against the afterload created byafterload column 60. The preserved organ may continue to beat in theworking state for the duration of the preservation period; up to orexceeding 24 hours.

According to the studies performed using perfusion system 10 to supportanimal hearts, the apparatus and method of the present invention allowthe preserved organ to be maintained in the beating state for up to 24hours or longer with minimal to no myocardial damage. As part of pilotstudies using animal hearts, blood electrolytes of donor heartsmaintained in the beating state were measured at one hour, six hour andtwelve hour intervals. Analysis of the blood electrolytes indicated thatthe levels of glucose, sodium (Na), chlorine (Cl), potassium (K),calcium (Ca) and bicarbonate HCO3 remained substantially at baselinelevels throughout the preservation period. Accordingly, the apparatusand method of the present invention allow a donor heart to be maintainedin the viable beating state for periods beyond the current four hourlimitation associated with current hypothermic arrest and storagetechniques.

Also associated with the apparatus and method of the present inventionare three separate chemical solutions operative in the preservation ofthe organ 12. As disclosed, the three chemical solutions replenish thepreserved organ with energy as it is consumed by the cellular activity,maintain the blood electrolytes at physiologic levels, and stimulate thecardiac conduction system for maintaining the donor heart in the beatingstate during the preservation period. The three chemical solutions areprovided to reservoir 30 through drip manifold 80 as previouslydiscussed, which assists in regulating the proper drip rate for eachchemical solution. The first solution is stored within IV bag 82, thesecond solution is stored within IV bag 84, and the third solution isstored within IV bag 86.

Prior to perfusing the organ 12, the perfusion system 10 is primed with100-250 ml of the primary solution (stored in IV bag 82), 12.5-25 mg ofMannitol (a complex sugar) or a suitable substitute, and preferably125-250 mg of methylprednisolone sodium succinate or a suitablesubstitute. The Mannitol acts as an impermeant to increase the osmoticpressure of the perfusate, which serves to minimize or reduce edemaformation in the preserved organ. Mannitol also acts as an oxygen orfree radical scavenger to attenuate the perturbations of reperfusioninjury and extracorporeal perfusion to the preserved organ. Moreover,the Mannitol is especially useful when the perfusate contact surfaces ofperfusion circuit 14 are non-heparin bonded. However, Mannitol can stillbe used within perfusion circuit 14 even when all of its components haveheparin bonded surfaces, so that the benefits provided by Mannitol canbe fully utilized. The methylprednisolone sodium succinate is a steroidwhich acts as a cell membrane stabilizer for avoiding cell lysing duringreperfusion and also acts as an immunosuppressive agent.

As disclosed, the first solution, or primary solution is a solutioncomprising sugar and various electrolytes. The first solution isformulated by combining several chemical components with preferably oneliter of dextrose, 5% (with a preferred range of between 2.5% and 5%dextrose) in normal saline (0.9 molar sodium chloride). Alternatively,the dextrose may be delivered in half normal saline (0.45 molar sodiumchloride). Dextrose is one of the major components needed by thepreserved organ for cellular energy and ATP production. The dextrose, aform of glucose, acts by stimulating the aerobic pathway of glycolysisand the Krebs' cycle; the primary biochemical processes for energyproduction in the body. To this dextrose solution is added, 4milliequivalents of potassium chloride (with a preferred range ofbetween 4 meq and 6 meq). The purpose of the potassium chloride is tomaintain normal physiologic levels of intra and extra-cellularpotassium, thus abolishing arrhythmias (abnormal heart rhythm).Preferably, 35 units of regular insulin (with a preferred range between20 units and 40 units) are also added to the primary solution. Insulinacts to drive glucose into the cells to make it readily available forthe cytoplasmic and mitochondrial metabolic processes. Insulin alsodrives extracellular potassium into the cells helping in achieving aphysiologic potassium level. Preferably, 1.5 grams of calcium chloride(with a preferred range of between 1.0 grams and 1.5 grams of calciumchloride) are also added. Calcium chloride is the primary cationrequired for myocardial muscle contraction, and its presence in normalphysiologic levels is important for maintaining the donor heart in thebeating or working state. The calcium chloride also acts as a positiveinotrope for increasing the force of myocardial contractility, againrequired for normal myocardial function during preservation of the donorheart in the beating state. The primary drip solution stored in IV bag82 is provided to drip manifold 80 at a preferred drip rate of 15 ml/hr(with a preferred range of between 15 ml/hr and 40 ml/hr). In analternate embodiment of the primary solution, preferably 5 ml of sodiumbicarbonate (with a preferred range of between 5 ml and 10 ml) is addedto the solution bag to maintain a normal pH of between 7.4-7.5. Thus,the addition of sodium bicarbonate acts to buffer the solution.

The second solution disclosed is preferably a fatty acid solution, i.e.,saturated and/or unsaturated monocarboxylic acids in solution. Bothshort chain and long chain fatty acids may be used including C₃ to C₁₀,C₃ to C₈ and preferably, C₃, C₇ or C₈ chain fatty acids. In thepreferred embodiment, this is achieved with a 20% intralipid solution(with a preferred range of between 10% and 20% being employed). Thepreferred concentrations of the intralipid solution are currentlyavailable from commercial manufacturers as a 10% intralipid solution ora 20% intralipid solution. Alternatively, soyacal may also be used whichprovides fatty acid and is derived from a soybean base. The intralipidsolution is provided to drip manifold 80 at a preferred rate of 2 ml/hr(with a preferred range of between 1 ml/hr and 2 ml/hr). The intralipidsolution is preferred for use with the present invention due to its highcontent of fatty acids, which can be directly metabolized by the cellsof the donor heart. The fatty acids are the primary source of energy forthe myocardial cell. The second source of energy for the myocardial cellis the glucose provided by the first drip solution.

The third solution disclosed is created by mixing preferably 250 ml ofnormal saline (with a preferred range of between 250 ml and 500 ml) withpreferably 4 mg of epinephrine (with a preferred range of between 4 mgand 8 mg of epinephrine). This solution is used to provide the donorheart with base-line levels of catecholamines necessary for normal heartrate and contractility. Epinephrin is also used to maintain the heartrate within a normal physiologic range. Epinephrin works by stimulatingthe receptors of the sympathetic nervous system in the preserved heart.Studies made in conjunction with the present invention have demonstrateda marked depletion of plasma catecholamines levels after 2-6 hours ofpreservation in the perfusion system 10, through multiple measurementsof serum catecholamine levels. The third solution is provided to dripmanifold 80 at a preferred drip rate of 4 ml/hr (with a preferred rangeof between 2 ml/hr and 12 ml/hr) for maintaining base-line levels ofcatecholamines. In an alternate embodiment of the third solution orepinephrine solution, preferably 2 ml of sodium bicarbonate (with apreferred range of between 2 ml and 5 ml) is added to the solution bagto maintain a normal pH of between 7.4-7.5. Thus, the addition of sodiumbicarbonate acts to buffer the solution.

Because the preserved organ 12 is maintained in the beating state, it isimportant that the heart be provided with oxygenated blood at thenormothermic temperature. The preserved organ should also be providedwith a balanced substrate consisting of the three disclosed chemicalsolutions. Additionally, since the preservation period is up to 24 hoursor longer, the preserved organ 12 should be provided with significantamounts of energy and replenished with various chemical compounds formaintaining the normal beating operation. As part of the alternativepreferred embodiment, the fatty acids can be delivered into the fluidmedia via solution bag 274, and the remaining chemical compositions canbe delivered into the fluid media via solution bag 272.

Turning now to FIG. 4, perfusion system 10 is shown as being installedon a mobile cart 140. As disclosed, cart 140 includes a top shelf 142, amiddle shelf 144, and a lower shelf 146 which are supported by fourposts 148. The lower end of each post 148 includes a locking caster 150.Associated with two of the posts 148 are a pair of adjustable poles 152,154. The height of each pole 152, 154 can be adjusted using a threadedlocking knob 156. Pole 154 includes an adjustable arm 158 which isprimarily intended for supporting lines 60 and 62 for setting the heightof the afterload column 60. Adjustable arm 158 also includes a threadedlocking knob 160 for setting the height of the adjustable arm 158 and ahook portion 162 at the outboard end thereof for supporting lines 60,62.

The top shelf 142 of cart 140 includes a circular aperture and annularclamp 170 for receiving and securing preservation chamber 20. Asdisclosed, preservation chamber 20 is placed into annular clamp 170 andsecured with a plurality of thumb screws 172. While not specificallyshown, annular clamp 170 and thumb screws 172 may be replaced with acircular clamp operated by a release lever for securing preservationchamber 20. Top shelf 142 is also provided with a square aperture 174which allows the various lines to pass from the preservation chamber 20down to the components below. Middle shelf 144 also includes a squareaperture 176 which provides a similar function. As disclosed, reservoir30 is positioned directly below preservation chamber 20 on the middleshelf 144. Middle shelf 144 also includes an oxygen bottle and regulator178 for providing the requisite oxygen and carbon dioxide mixture tomembrane oxygenator 38. The bottom shelf 146 is particularly well suitedfor supporting the centrifugal pump 34, membrane oxygenator 38, andwater heater 40. Since these are typically the heaviest componentsassociated with perfusion system 10, the location of these components onbottom shelf 146 serves to lower the overall center of gravity whichfurther stabilizes mobile cart 140. Top shelf 142 provides ample surfacearea for supporting the flow meter 70 and the digital pressure recordingsystem 74. However, additional electronic monitoring and feedbackdevices could also be supported by top shelf 142 for use with perfusionsystem 10. Finally, a clear hard plastic cover 180 can be fitted on topof cart 140. Cover 180 allows visual inspection of the componentsstationed on top shelf 142, while also providing additional protectionto the perfusion system 10 and preservation chamber 20.

As will be appreciated by one skilled in the art, mobile cart 140provides significant enhancement to the overall function of perfusionsystem 10. More specifically, perfusion system 10 may be wheeled intothe operating room from a separate storage location. Additionally, thecart 140 may be easily moved within the operating room or rooms duringboth organ harvesting and organ implantation. Moreover, the lockingcasters 150 allow cart 140 to be fixed in one location to preventunwanted movement. The overall size of mobile cart 140 is such that itcan be easily transported in both land based vehicles, such as anambulance, or within private or commercial aircraft, such as a hospitalhelicopter or airplane. Accordingly, mobile cart 140 serves to increasethe overall efficiency of transporting a harvested organ forimplantation into the recipient.

Turning now to FIG. 5, the preservation system 200 of the presentinvention is shown in accordance with another preferred embodiment. Itshould be noted that preservation system 200 shares many similarcomponents, and operates in a similar fashion as perfusion system 10disclosed above. Thus, preservation system 200 also serves to reduce oreliminate time dependent ischemia associated with the prior techniques,minimize or eliminate edema, and deliver chemical enhancements to thepreserved organ in a physiologic fashion. However, several improvementsare discussed in association with preservation system 200 which will bedescribed in more detail below. The present configuration ofpreservation system 200 also allows the donor heart 12 to be harvestedin either the beating state or non-beating (arrested) state, andconnected to preservation system 200 where the organ is maintained inthe beating state and provided with a physiologic coronary flow of thepreservation fluid.

As specifically shown in FIG. 5, the physiologic coronary flow isprovided in a pulsatile fashion because the heart is beating in theworking state for generating its own pulsatile flow. As discussed above,a particular advantage of the present invention is that the fluid mediaused to extend the preservation period is comprised primarily ofautologous, homologous, or compatible blood which is circulated throughpreservation system 200. The chemical enhancements described herein arethen combined with the blood for creating the preservation fluid media.Thus, the donor heart 12 is provided with oxygen and various chemicalenhancements during the preservation and maintenance period formaintaining the organ in a viable state. For purposes of the presentinvention, viable state means a state in which the organ is functioningat any physiological level. Moreover, cellular waste and metabolites arecarried away from the organ in a normal physiologic fashion and filteredout of preservation system 200. Alternatively, the cellular waste andmetabolites can be diluted or reduced from within preservation system200 by transfusing the blood within the reservoir. Additional cellularwaste and metabolites can be removed with a suitable hemodialysisfilter.

Preservation system 200 is designed to simulate the in-vivo humancardiovascular system for maintaining the donor heart 12 in the beatingstate for periods up to or exceeding twenty-four (24) hours. Thepreservation technique can be operated at a normothermic temperature ofabout 37° C., or at a substantially normothermic temperature of about20° C. to about 37° C. As disclosed above, preservation system 200comprises a closed preservation circuit 202 for circulating a fluidmedia, comprised of autologous blood, or alternatively homologous orcompatible blood or blood substitute, and other chemical compositionscomprising a preservation solution, to donor heart 12. As disclosed, theblood may be either whole blood or leukocyte depleted whole blood whichis compatible with the organ. As shown, preservation circuit 202includes one or more arterial lines 16 for providing oxygenated fluid todonor heart 12, and one or more venous lines 18 for carrying depletedfluid away from donor heart 12. According to this embodiment, thearterial lines 16 comprise the delivery means for delivering the fluidmedia to at least one major vessel of the organ, and the venous lines 18comprise the means for carrying the fluid media away from the organ. Aspart of the method of the present invention, the arterial lines 16 areused for supplying fluid and/or perfusing donor organ 12 in either thenon-working and working states.

With continued reference to FIG. 5, donor heart 12 is shown as beingconnected to preservation circuit 202. The donor heart 12 is enclosedwithin containment means for containing the donor heart in communicationwith the fluid media. As disclosed, the containment means is a hardplastic chamber for protecting and allowing visualization of thepreserved organ. It is preferable that the containment means orpreservation container 206 is made from clear polycarbonate, or othersuitable hard plastic material. As disclosed, the containment means 206may also comprise a thick, yet soft flexible plastic container in theform of a bag having a single or double zip-lock closure. Preferably,the bag is formed to accommodate the contour and shape of the preservedorgan, such as donor heart 12, or any other solid organ.

As shown, preservation container 206 forms part of an integratedpreservation device 204 which also includes a hollow fiber membraneoxygenator 208 and a heat exchanger 210. As part of this embodiment,oxygenator 208 comprises the oxygenation means for oxygenating at leastpart of the fluid media, and heat exchanger 210 along with itsassociated water heater/cooler unit 236 for providing temperaturecontrolled water comprises the temperature control means for maintainingthe temperature of the organ at a temperature of about 20° C. to about37° C., As will be appreciated, preservation container 206 issubstantially similar to preservation chamber 20 disclosed above.However, as part of the present invention, preservation container 206 isslightly larger for simultaneously defining a fluid reservoir 212 forstoring a supply of the preservation fluid or fluid media. As shown, itis preferable that preservation container 206 be large enough fordefining a fluid reservoir 212 for containing approximately 500-3000 mlof fluid. This design feature allows donor heart 12 to be substantiallyimmersed and/or bathed within the fluid within preservation container206, if desired.

Preservation container 206 has an open top, and is defined by agenerally cylindrical side wall 90, and having a sloped bottom 92 whichpromotes the flow of fluid into reservoir outlet 222. The top ofcylindrical side wall 90 also includes an outwardly protruding flange 94around its circumference for providing an additional surface forreceiving the cover assembly 22 shown in FIG. 2. The remaining portionsof cover assembly 22 are substantially similar to that disclosed aboveexcept for the addition of multiple blood inlets or ports 292 and one ormore safety valves 294.

Preservation container 206 also includes a pair of filters 214 whichserve to remove particulate matter from the preservation fluid. Eachfilter 214 preferably comprises a polyurethane sponge. Accordingly,filters 214 comprise at least a portion of the filtering means forremoving unwanted filtrate from the fluid media. One side of each filter214 includes a silicone defoaming screen 216 which further assists inreducing and/or removing bubbles and foam from the recirculatingpreservation fluid. A silicone foam pad 218 is positioned within thelower portion of preservation container 206 for supporting donor heart12 during the preservation period. The silicone foam 218 also acts as asponge for shock absorption. As shown, an additional port 224 having astopcock 226 is also provided for instances in which it is desirable todrain the preservation fluid within fluid reservoir 212 while thepreservation circuit 202 is being operated. Such an instance mightinclude transfusing the blood contained in reservoir 202 for removingunwanted metabolites.

An outlet line 228 is provided for connecting reservoir outlet 222 witha centrifugal pump head 230. A pump head driver 232 is provided forgenerating the rotational force and control which is provided to pumphead 230. The preferred pump head and pump for this application is theBiomedicus 550, manufactured by Medtronic, Inc. which propels the bloodvia magnetic field driven cones and includes a biocompatible surface,which minimizes hemolysis of the blood. As will be appreciated,centrifugal pump head 230 and driver 232 comprises both the pressurecontrol means for controlling the pressure of the fluid media, and theflow control means for controlling the flow of at least part of thefluid media.

The centrifugal pump 230 propels the blood and preservation fluid viapump outlet line 234 into the integrated heat exchanger 210 which warmsor cools the preservation fluid to a predetermined temperature. While itis preferred that donor organ 12 be maintained at a normothermictemperature of approximately 37° C., integrated heat exchanger 210 canalso be used to lower the temperature of the preservation fluid down toa temperature of approximately 20° C. This heating and cooling functionis performed by a water heater/cooler unit 236 which circulatestemperature controlled water through the water side 238 of heatexchanger 210 via water circuit lines 240. The preservation fluidcirculates through the second fluid side 242 of integrated heatexchanger 210 where it achieves the desired temperature.

The temperature controlled preservation fluid then flows throughconnecting line 244 and into the integrated membrane oxygenator 208. Aspart of this embodiment, the blood within the preservation fluid isoxygenated using a preferred mixture of 95%-97% O2 and 3%-5% CO2 at arate of 1-5 L/min by membrane oxygenator 208. This mixture is providedto oxygenator 208 via input/output lines 246. As set forth above, thepreferred oxygenator is a hollow fiber oxygenator, such as the Monolythoxygenator manufactured by Sorin Biomedical or the MINIMAX PLUSmanufactured by Medtronic. While not specifically shown in FIG. 5,membrane oxygenator 208 is provided with the requisite oxygen and carbondioxide mixture from a regulated oxygen bottle 178 (FIG. 4). Theoxygenator 208 further includes a plurality of outlets which allow thepressurized preservation fluid to be directed to other devices. Itshould be understood that at least one of the outlets from oxygenator208 includes an integrated temperature monitoring probe (not shown)which can be used for monitoring the temperature of the fluid mediaexiting the oxygenator. More specifically, first outlet line 248provides preservation fluid to an arterial filter 252. Preferably,filter 252 is a twenty (20) micron arterial filter, such as thepediatrics arterial filter manufactured by Medtronic. A second outletline 250 serves as a recirculation line and provides preservation fluidto a leukocyte filter 254. Preferably, filter 254 is a micron leukocytefilter, such as the Pall leukocyte depleting filter manufactured by PallFilters. Accordingly, filters 252 and 254 comprise the filtering meansfor removing the unwanted filtrate from the fluid media.

The output of arterial filter 252 is connected to a selector valve 50via filter output line 48. Selector valve 50 is a multi-positionstopcock which may be placed in one of several positions for directingfluid flow to either the initial perfusion line 52 (for antegradeperfusion via the aorta), the left atrium supply line 54 (for antegradeperfusion via the left atrium), or both lines simultaneously (forpriming purposes). Additionally, selector valve 50 may be turned offcompletely. As previously discussed, lines 48, 54, and at times lines 52and 58 form the arterial side 16 or delivery means of preservationcircuit 202. The terminal end of the initial perfusion line 52 isconnected into a tee or Y connector 56 which then branches to aorta line58 and the afterload column, line 60. One end of tee 56 also includes apressure transducer 256 which allows the pressure of the preservationfluid and more specifically the aortic root pressure to be monitored bya central signal processor and controller 560. A straight connector 258is provided for connecting the adjustable height afterload column line60 with the aorta return line 62. A luer port 63 having an anti-siphonvalve secured to a stopcock thereon is integrated with connector 258which acts as a one-way valve for allowing fluid pumped across connector258 to flow through aorta return line 62 without syphoning additionalfluid from afterload line 60.

The distal end of the afterload line 60 is attached to one of theconnectors on a three-way port 260 for returning the preservation fluidto reservoir 212. As discussed above, aorta line 58 providesbi-directional flow to and from donor heart 12, depending upon whichmode the preservation system 200 is operating. Additionally, the heightof afterload column 60 is adjustable between a range of verticalpositions for selectively changing the afterload pressure against whichthe donor heart 12 will beat or pump. It is contemplated that the heightof afterload column 60 is adjusted by a feedback controlledelectromechanical device in response to the coronary flow and aorticand/or left ventricle pressure signals received by controller 560. Oncethe preservation fluid pumped through afterload column 60 crossestopcock connector 258 and anti-siphon luer port 63, it is returned tofluid reservoir 212 via aorta return line 62 by gravity. Additionally, aright ventricle return line 64 is connected between three-way port 260and the cannula 122 of the pulmonary artery 132 for returning coronaryeffluent to fluid reservoir 212. Accordingly, lines 58, 60, 62 and 64form the venous side 18 of preservation circuit 202 as they providemeans for carrying fluid media away from the heart.

The aortic flow is measured by an ultrasonic flow probe 66 which is partof aorta line 58. Likewise, an ultrasonic flow probe 68 measures thecoronary blood flow through right ventricle return line 64 of coronaryeffluent from the right ventricle to the fluid reservoir 212. Thesignals produced by flow probes 66, 68 are provided to inputs 66A, 68A,respectively, on system controller 560. Alternatively, the aortic andcoronary flow signals produced by ultrasonic flow probes 66 and 68 arereceived by a multi-channel data recorder/controller such as flowmeter70 shown in FIG. 1 or flowmeter 562 shown in FIG. 11 having at least twochannels which assists in monitoring the condition of the donor heart12, and the overall performance of preservation system 200. Aspreviously discussed, one preferred flowmeter is the two-channelflowmeter manufactured by Transonic Systems. However, it is contemplatedwith this embodiment that a central controller 560 receive the signalsproduced by the various transducers as feedback signals, therebymonitoring all relevant signals from one central station. Alternatively,the signals from pressure transducers 72 and 256 may be monitored by amulti-channel data recorder and displayed on a lap top computer 564. Thepreferred device is an integrated hardware/software system such as theMacLab.® manufactured by ADInstruments, Inc. These feedback signals canthen be used for monitoring and controlling the pressure and flowprovided by pump 230 via control line 580, as well as the temperature ofheat exchanger 210 via bidirectional control line 582. Also shown isthat central processor or controller 560 receives a temperature feedbacksignal 584 from the temperature probe output (not shown) of oxygenator208.

The coronary flow is maintained within acceptable physiologic ranges(300-500 m/min) by adjusting the height of the afterload column 60 abovethe heart 12 and adjusting the flow rate generated by pump 230. Theafterload pressure is maintained at approximately 70 mm of mercury, butmay be adjusted as necessary. A micro-tip pressure catheter 72 isinserted into the left ventricle via the left atrium 134 for measuringthe intracavitary pressures of donor heart 12. A preferred pressurecatheter 72 is of the type manufactured by Millar Instruments. Allpressure measurements generated by pressure catheter 72 are recorded anddisplayed using a digital pressure recording system 74 such as thatmanufactured by Maclab which also assists in monitoring the condition ofthe preserved organ 12. As disclosed, pressure recording system 74 iscapable of recording and displaying multiple pressure measurements.Alternatively, the signal generated by pressure catheter 72 may bereceived by central controller 560 on line for storage or display 72A.

As part of the present invention, it is contemplated that controller 560also operate a mechanical actuator or arm 566 (FIG. 11) which is capableof automatically adjusting the height of afterload column 60 during thepreservation period. This can be achieved through monitoring the flowsignals produced by flow probe 66, 68 and the pressure signals producedby pressure transducer 256 and pressure catheter 72 which as shown arereceived by controller 560 on lines 256A and 72A, respectively.

Optionally, a pacemaker and internal defibrillator 220 may be connectedto the ventricular walls of the preserved heart 12 via pacing leads 221to correct by DC shock any unexpected arrhythmias during thepreservation period.

A second port from oxygenator 208 provides outlet line 250 withoxygenated blood which is carried to leukocyte filter 254. Outlet line262 from filter 254 delivers the preservation fluid to a hemodialysisfilter 264 which is positioned in series with line 262 between a firststopcock 266 and a second stopcock 268. Hemodialysis filter 264 servesto remove metabolic waste products which may be produced by thepreserved organ. The preferred hemodialysis filter 264 for thisapplication is that manufactured by Cobe or Baxter.

The outlet from stopcock 268 provides the filtered blood to a two-portdrip manifold 270 which receives the first and second preservationsolutions from solution bags 272 and 274, respectively. As shown, dripmanifold 270 includes two stopcock valves which assist in controllingthe delivery of the chemical solutions of the present invention to thepreservation fluid flowing through drip manifold 270. The outlet line276 of drip manifold 270 is connected to three-way port 260 fordelivering the enhanced preservation fluid back into fluid reservoir212. While not specifically shown, it should be understood that aninfusion pump is inserted between each solution bag 272, 274 and dripmanifold 270 for individually controlling and regulating the drip rateof the chemical solutions contained in drip bags 272, 274 into dripmanifold 270 as is well known in the art.

A variety of materials may be used for creating the various lines andcomponents of preservation system 200. As almost all of the lines andcomponents of preservation circuit 202 are in constant contact with thepreservation fluid media, it is desirable to suppress the acuteinflammatory response caused by exposure of the blood within the fluidto extracorporeal artificial surfaces. To alleviate this problem, all ofthe contact surfaces within perfusion circuit 14 may be coated or bondedwith heparin to reduce complement and granulocyte activation. As analternative, heparin may be directly introduced into the fluid mediacirculating through preservation circuit 202, or other bio-compatiblesurfaces may be utilized in circuit 202. The introduction of heparinassists in minimizing blood clotting within the circuit.

With continued reference to FIG. 5, the operation of preservation system200 will be described in more significant detail. As described above,the donor heart is harvested in either the beating state or thenon-beating or arrested state and placed into preservation container206. At this point, centrifugal pump 230 is propelling oxygenated andrewarmed blood through line 248. During priming, selector valve 50 isplaced into the position which allows blood to flow simultaneouslythrough the initial perfusion line 52 and the left atrium supply line54. Once the arterial lines 16 of preservation circuit 202 aresufficiently primed to remove the presence of any air bubbles or airpockets, valve 50 is rotated into the position for supplying initialperfusion line 52 with fluid. Aortic line 58 can then be connected andsecured to the aorta 130 using aortic cannula 120. This procedure allowsblood to flow to the aortic line 58 for immediate perfusion of donorheart 12 via the aorta 130 in the non-working beating state.

Optionally, the stopcock on connector 258 may be closed for maximizingblood flow into the aorta 130. This procedure of antegrade perfusion viathe aorta 130 is performed for approximately 10-15 minutes to allow fordonor organ stabilization and to provide a period for instrumentation tobe established. During this instrumentation period, the remaining flowlines are connected to donor heart 12. More specifically, the connectionbetween aorta line 58 and the aorta 130 is completed and checked forleaks, supply line 54 is connected to the left atrium 134, and the rightventricle return line 64 is connected to the pulmonary artery 132. Thepulmonary veins and superior and inferior vena cavae are then tiedclosed using surgical suture. During the initial connection protocol,any blood overflow is contained within preservation container 206 andreturned to reservoir 212.

At the end of the stabilization period, the flow to the aorta 130 isreduced by rotating selector valve 50 to the normal operating positionwhich simultaneously and gradually increases the flow to the left atrium134 via left atrium supply line 54 and gradually shuts off flow throughinitial perfusion line 52. The stopcock of connector 258 is then openedwhich allows blood to flow through afterload line 60 and return line 62.This procedure then switches the donor heart 12 from the non-workingstate into the working state to ensure pulsatile coronary flow delivery,in which blood is pumped through the return lines 18 of preservationcircuit 202 by the donor heart 12.

Blood flow to donor heart 12 through arterial or delivery lines 16 isassisted by centrifugal pump 230. The flow rate, pressure andtemperature is monitored by controller 560 which adjusts the speed ofpump head 230 for controlling the pressure and flow rate of thepreservation fluid. The donor heart 12 is allowed to beat against anafterload pressure created by the vertical position of afterload column60 above the preservation chamber 20 thereby generating a pulsatilecoronary flow. Additionally, oxygenated blood is provided to thecoronary vascular system, and de-oxygenated blood from the coronaryvascular system is pumped from the right ventricle into the pulmonaryartery return line 64 and returned to reservoir 212. At this point,donor heart 12 can be maintained in the viable beating state for theduration of the preservation period.

Turning now to FIG. 6, an alternate configuration of preservation system200 is shown. As will be appreciated, the preservation system 200illustrated in FIG. 6 comprises many of the components illustrated inFIG. 5. However, the primary distinguishing feature is that a pulsatilecoronary flow is provided to donor heart 12 as opposed to anon-pulsatile or semi-constant flow. As such, this configuration allowsseveral of the fluid carrying lines to be eliminated because the donorheart 12 is preserved in a beating non-working state.

In this embodiment, preservation system 200 includes a similarintegrated preservation device 204 which includes the integratedpreservation container 206 and reservoir 212, a hollow fiber membraneoxygenator 208, and an integrated heat exchanger 210. Oxygenator 208 andheat exchanger 210 are operated in substantially the same fashion asdescribed above. As previously discussed, the preservation fluid storedwithin reservoir 212 flows through reservoir outlet 222 for delivery toa pulsatile pump 280 via outlet line 228. The pulsatile pump 280 isdriven by a pulsed the electric control unit 282. The preferredpulsatile pump for this application is either the Heartmate electricassist pump manufactured by Thermo Cardiosystems, Inc., or the Novacor®left ventricular assist pump manufactured by Baxter HealthcareCorporation. Alternatively, there are other pulsatile pumps which aredesigned to less rigorous specifications which are also compatible withthe preservation circuit 202 of this embodiment and which provide thefunction of pulsatile flow at a lower cost.

Accordingly, pulsatile pump 280 generates a pulsatile flow, as opposedto the constant flow produced by centrifugal pump 230. The flow ofpreservation fluid through heat exchanger 210 and oxygenator 208 issubstantially similar to that described above. First outlet line 248then carries the preservation fluid to arterial filter 252. The outletof filter 252 is connected to a stopcock connector 284 having a similarpressure transducer 256 formed as an integral part thereof. Thepreservation fluid then flows through aorta delivery line 286 and intothe aorta 130 via the aorta cannula 120. The pressure of the fluid indelivery line 286 can be monitored through pressure transducer 256. Thismethod of delivering preservation fluid to the aorta 130 in the reversedirection allows the coronary vascular system to be perfused with thefluid media comprising oxygenated blood and the various chemicalenhancers of the present invention. The coronary effluent is then pumpedthrough the pulmonary artery 132 and into cannula 122. This coronaryeffluent is then carried through pulmonary artery return line 288 andback into fluid reservoir 212. It should be noted that re-circulationline 250 as well as the various components disposed there along,including leukocyte filter 254, hemodialysis filter 264 and dripmanifold 270 operate in substantially the same manner as describedabove. Also shown is that aorta delivery line 286 and pulmonary arteryreturn line 288 each include an ultrasonic flow probe 66, 68(respectively) for measuring the flow rates through the delivery andreturn lines.

As part of the alternate configuration of FIG. 6, preservation container206 is similarly sized for containing donor heart 12 and defines a fluidreservoir 212 for storing about 500-3000 ml of the fluid media. However,only one polyurethane filter 214 and one silicone defoaming screen 216is utilized. As will be appreciated, this modification to preservationcircuit 202 allows the use of only one line or delivery means forcarrying oxygenated blood to the aorta 130, for supplying the coronaryarteries using an antegrade perfusion technique, and one line or meansconnected to the pulmonary artery for carrying the coronary effluent(deoxygenated blood) away from the donor heart 12. Accordingly, there isno need for any additional cannulae or perfusion lines in communicationwith the left atrium due to the pulsatile flow provided by pulsatilepump 282. This pulsatile flow provides the physiologic characteristicsof coronary flow for preventing coronary spasms, coronary endothelialdamage, and for ensuring proper micro circulation for the preservedorgan. By preserving donor heart 12 in the beating non-working state, areduction in oxygen consumption and a reduction of stress of pumpingagainst an afterload column can be achieved. This further results in areduction in cellular metabolism and cellular waste, leading to aprolonged preservation period. Optionally, an intra-cardiac vent may beplaced in the left ventricle to drain any blood that may leak throughthe aortic valve.

As part of the alternate configuration, preservation container 206 issimilarly sized for containing donor heart 12 and defines a fluidreservoir 212 for storing about 500-3000 ml of the fluid media. However,an internal divider is present to separate the fluid media from thestored organ (not shown). In this configuration, the organ is placed inthe top portion of the reservoir, separated from the fluid media of thecircuit. This configuration allows for complete visualization of thepreserved organ, during the preservation and transportation period.

While preservation of a donor heart which is intended fortransplantation has been described above, it is within the scope of thepresent invention that preservation system 200 can also be used formaintaining a heart during reconstructive or other types of surgery.Accordingly, this procedure provides that an individual's heart can beremoved and placed into the preservation circuit 202 of the presentinvention and operated upon outside of the body. In this scenario, thepatient can be temporarily maintained with a suitable bypass andheart/lung machine as is well known in the art. However, removing theheart or any other organ for corrective surgery and maintaining theorgan in a viable state allows procedures which are normally consideredcomplicated and high risk to be easily performed on the organ outside ofthe body. Once the surgery to the organ is complete, the organ isreimplanted into the original patient. Another application is removingand maintaining an organ and also perfusing the organ withchemotherapeutics for cancer treatment. Upon completion of the chemoprocedure, the organ can be reimplanted. This technique would beespecially useful for treating cancer of the liver, kidney or pancreas.Accordingly, the preservation system 200 according to the teachings ofthe present invention provides for a variety of applications in additionto maintaining a donor organ for transplantation in a viable state.

With reference now to FIGS. 7-10, alternate embodiments of thepreservation system according to the teachings of the present inventionare disclosed. Upon reviewing the following description, it will beappreciated that the preservation system of the present invention canalso be utilized for preserving various solid organs including, but notlimited to, the kidney, liver, lungs, pancreas, small intestine, andmyocutaneous free flaps which can be used for transplantation to severeburn or trauma patients, or even cancer patients. The preservationsystem can also be used to maintain various vessels, such as the aorta,and vein grafts in a viable state for transplantation or plastic andreconstructive surgery. According to this aspect of the invention, thesolid organ to be preserved or maintained in a viable state is containedwithin a soft shell bag which is specifically designed for theparticular organ. At least one artery and one vein is cannulated so thatthe preservation fluid including compatible blood can be delivered toand carried away from the organ. Accordingly, the preservation circuitrequired for this alternate configuration is similar to that used forpreserving a donor heart as described above.

With specific reference to FIG. 7, the preservation system 300 forpreserving a kidney 310 is shown. The kidney preservation circuit 302 isoperational for delivering oxygenated fluid to kidney 310 and carryingdepleted fluid away from the kidney 310. Kidney preservation circuit 302also utilizes an integrated preservation device 204 which defines apreservation container 206 and fluid reservoir 212, a heat exchanger210, and an oxygenator 208. The warmed and oxygenated preservation fluidis carried from one port of oxygenator 208 to an arterial filter 314 viaoutlet line 312. An ultrasonic flow probe 316 measures the flow ratethrough line 312. Line 312 terminates at arterial stopcock connector318. A pressure transducer 320 is formed at the opposite end of stopcockconnector 318 and also connects to the arterial fitting 322 of the softshell bag. An arterial cannula 324 is inserted within arterial fitting322 and extends within the preservation chamber 364 of soft shell bag360. Arterial cannula 324 then connects to the renal artery 326 fordelivering the oxygenated preservation fluid to donor kidney 310. In asimilar fashion, return line 328 extends between the top cover assembly22 of fluid reservoir 212 and the venous stopcock connector 330. Anultrasonic flow probe 356 is also disposed along return line 328 formonitoring the returned flow of depleted fluid. The opposite end ofconnector 330 also includes a pressure transducer 332 which is used formonitoring the pressure of the depleted fluid media transported awayfrom donor kidney 310. Pressure transducer 332 connects to venousfitting 334 which also includes a venous cannula 336 inserted therein.It is preferred that venous fitting 334 also be integrally formed withsoft shell bag 360. Venous cannula 336 connects to the renal vein 338 ofdonor kidney 310. The ureter 340 of kidney 310 is connected to a uretercannula 342 which is also integrated with a ureter connector 348 forcarrying urine through line 344 and into graduated vessel 346. Astopcock connector 348 is provided along line 344 to allow the flowthrough line 344 to be halted in cases where vessel 346 must be changed,or where the urine must be sampled. Additionally, fluid may be releasedfrom vessel 346 through stopcock 354. The graduations on vessel 346allow the urine production of kidney 310 to be monitored during thepreservation period.

As with the other related embodiments, oxygenator 208 includes a secondrecirculation line 250 which delivers temperature controlled andoxygenated preservation fluid to a leukocyte filter 254 and an optionalhemodialysis filter 264. The outlet of filter 264 connects to a similartwo-port drip manifold 270 which receives the chemical solutions atvarious drip rates from solution bags 272, 274. The enhancedpreservation fluid is returned to reservoir 212 via return line 276. Thedrip rates of the chemical solutions are controlled by a suitableinfusion pump (not shown) as described above. As will be appreciated,either a centrifugal pump 230 or a pulsatile pump 280 can be used forcirculating the fluid media through the circuit for preserving any ofthe solid organs.

The containment means associated with kidney preservation circuit 302comprises a generally rectangular plastic bag 360 which includes asealed body portion 362 and a preservation chamber 364. A defoamingmaterial line the soft shell (not shown), an inner zip-lock closure 366and an outer zip-lock closure 368 are situated at the outer perimeter ofpreservation chamber 364. Accordingly, these closures 366, 368 define aflap 370 which can be unzipped and opened with respect to the sealedbody portion 362 for allowing the organ to be inserted and properlycannulated as described above. Closures 366, 368 are then sealed forcontaining the organ and defining the preservation chamber 364.Reinforcing members 384, which are formed by a heat seal, are located atthe terminal ends of closures 366, 368. Two zip-lock closures 366, 368are provided (as opposed to one) for enhanced structural rigidity, aswell as for providing a primary seal and a secondary seal to preventunwanted leaks of any residual fluid within preservation chamber 364. Avent assembly 372 is integrated within body portion 362 and extendsbelow both zip-lock closures 366, 368 and into preservation chamber 364.The top of vent 372 includes a stopcock valve 374 which allows air to beextracted from or placed into preservation chamber 364. Additionally, itis contemplated that preservation chamber 364 could be filled with abio-compatible fluid such as saline, or even a pharmaceutically activefluid through vent 372 after properly sealing flap 370.

Kidney preservation bag 360 may also be provided with one or morereinforcing ribs 376 which provide additional structural rigidity to thepreservation bag and assist in maintaining a consistent shape.Additionally, a hole 378 is provided within each corner of preservationbag 360 which allows the bag to be suspended from a horizontal supportmember 380 by a pair of bag hangers 382. A particular advantage of thesoft shell bag 360 is that ultrasound testing can be performed withkidney 310 remaining in bag 360 because the ultrasound probe can beplaced against the organ while being protected by the bag.

Turning now to FIG. 8, the preservation system 300 for preserving aliver is shown. The liver preservation circuit 304 is operational fordelivering oxygenated fluid media to liver 390 and carrying depletedfluid away from the liver 390. Liver preservation circuit 304 alsoutilizes an integrated preservation device 204 which defines apreservation container 206 and fluid reservoir 212, a heat exchanger210, and an oxygenator 208. The warmed and oxygenated preservation fluidis carried from one port of oxygenator 208 to an arterial filter 314 viaoutlet line 312. An ultrasonic flow probe 316 measures the flow ratethrough line 312 as described above. At this point, line 312 branchesinto two lines, one terminating at arterial stopcock connector 392, andthe other branch terminates at arterial stopcock connector 394. Eachstopcock connector 392, 394 also includes a pressure transducer 396,398(respectively) formed at the opposite end thereof. Connector 392 alsoconnects to arterial fitting 400 which is integrally formed with thesoft shell bag. A suitable cannula 402 is inserted within arterialfitting 400 and extends within the preservation chamber 444 of softshell liver bag 440. Cannula 402 then connects to the portal vein 404for delivering the oxygenated preservation fluid to donor liver 390. Thearterial stopcock connector 394 also connects to the arterial fitting406 of the soft shell bag. An arterial cannula 408 is inserted withinarterial fitting 406 and extends within the preservation chamber 444 ofsoft shell bag 440. Arterial cannula 408 then connects to the hepaticartery 410 which branches for delivering the oxygenated preservationfluid to right and left lobes of donor liver 390. In a similar fashion,a return line 412 extends between the top cover assembly 22 of fluidreservoir 212 and the return stopcock connector 414 which in turnconnects to return fitting 416, also integrally formed within soft shellbag 440.

As shown, the inferior vena Cava 418 remains open and uncannulated sothat the depleted preservation fluid can flow directly therefrom intopreservation chamber 444. Accordingly, return fitting 416 provides anoutlet for the depleted fluid to flow from and into return line 412. Anultrasonic flow probe 420 is disposed along return line 412 formonitoring the returned flow of depleted fluid. The gallbladder 422,still attached to liver 390, is connected to a suitable gallbladdercannula 424 which is also inserted with fitting 426. Stopcock connector428 is connected to fitting 426 for regulating the flow of bile throughline 430 and into graduated vessel 346. Stopcock connector 428 alsoallows the flow through line 430 to be halted in cases where vessel 346must be changed or for sampling bile. Additionally, fluid may bereleased from vessel 346 through stopcock 354. The graduations on vessel346 allow the bile production of gallbladder 422 to be monitored duringthe preservation period.

As with the other related embodiments, oxygenator 208 includes a secondrecirculation line 250 which delivers temperature controlled andoxygenated preservation fluid to a leukocyte filter 254 and an optionalhemodialysis filter 264. The outlet of filter 264 connects to a similartwo-port drip manifold 270 which receives the chemical solutions atvarious drip rates from solution bags 272, 274. The enhancedpreservation fluid is then returned to reservoir 212 via return line276. The drip rates of the chemical solutions are controlled by asuitable infusion pump (not shown) as described above.

The containment means associated with liver preservation circuit 304also comprises a generally rectangular plastic bag 440 which includes asealed body portion 442 and a preservation chamber 444. It should benoted that liver bag 440 shares many of the same components with kidneybag 360, which are described below.

An inner zip-lock closure 366 and an outer zip-lock closure 368 aresituated at the outer perimeter of preservation chamber 444.Accordingly, these closures 366, 368 define a flap 370 which can beunzipped and opened with respect to the sealed body portion 362 forallowing the organ to be inserted and properly cannulated as describedabove. Closures 366, 368 are then sealed for containing the organ anddefining the preservation chamber 364. Reinforcing members 384, whichare formed by a heat seal, are located at the terminal ends of closures366, 368. Two zip-lock closures 366, 368 are provided (as opposed toone) for enhanced structural rigidity, as well as for providing aprimary seal and a secondary seal to prevent unwanted leaks of anyresidual fluid within preservation chamber 364. A pair of ventassemblies 372 are integrated within body portion 362 and extend belowboth zip-lock closures 366, 368 and into preservation chamber 444. Thetop of each vent 372 includes a stopcock valve 374 which allows air tobe extracted from or placed into preservation chamber 444. Additionally,it is contemplated that preservation chamber 444 could be filled with abio-compatible or even a pharmaceutically active fluid through vent 372after properly sealing flap 370.

Liver preservation bag 440 may also be provided with one or morereinforcing ribs 376 which provide additional structural rigidity to thepreservation bag and assist in maintaining a consistent shape.Additionally, a hole 378 is provided within each corner of preservationbag 440 which allows the bag to be suspended from a horizontal supportmember 380 by a pair of bag hangers 382.

Turning now to FIG. 9, the preservation system 300 for preserving apancreas 450 is shown. The pancreas preservation circuit 306 is alsooperational for delivering oxygenated fluid media to pancreas 450 andcarrying depleted fluid away from the pancreas 450. As shown, thepancreas 450 is harvested along with the duodenum 452. Pancreaspreservation circuit 306 also utilizes an integrated preservation device204. The warmed and oxygenated fluid media is carried from one port ofoxygenator 208 to an arterial filter 314 via outlet line 312. Anultrasonic flow probe 316 measures the flow rate through artery line312. Line 312 terminates at arterial stopcock connector 454. A pressuretransducer 456 is formed at the opposite end of stopcock connector 454and also connects to the arterial fitting 458 which is integrally formedwith the soft shell bag. An arterial cannula 460 is inserted withinarterial fitting 458 and extends within the preservation chamber 494 ofsoft shell bag 490. Arterial cannula 460 then connects to thepancreatico/duodenal artery 462 for delivering the oxygenatedpreservation fluid to the pancreas 450. In a similar fashion, returnline 464 extends between the top cover assembly 22 of fluid reservoir212 and the venous stopcock connector 466. An ultrasonic flow probe 465is disposed along return line 464. The opposite end of connector 466also includes a pressure transducer 468 which is used for monitoring thepressure of the depleted fluid media transported away from pancreas 450.Pressure transducer 468 connects to venous fitting 470 which alsoincludes a venous cannula 472 inserted therein. It is preferred thatvenous fitting 470 also be integrally formed within soft shell bag 490.Venous cannula 472 connects to the splenic and/or portal vein 474 ofpancreas 450. The pancreatic duct 476 of pancreas 450 is connected to anappropriately sized cannula 478 which is also inserted within anintegrated cannula fitting 480 for carrying pancreatic juices throughline 344 and into a similar graduated vessel 346. A stopcock connector482 is provided along line 344 as described above to allow the flowthrough line 344 to be halted in cases where vessel 346 must be changed.Additionally, fluid may be released from vessel 346 through stopcock354. The graduations on vessel 346 allow the pancreatic juice productionof pancreas 450 to be monitored during the preservation period.

As with the other related embodiments, oxygenator 208 includes a secondrecirculation line 250 which delivers temperature controlled andoxygenated fluid media to a leukocyte filter 254 and an optionalhemodialysis filter 264. The outlet of filter 264 also connects to atwo-port drip manifold 270 which receives the chemical solutions atvarious drip rates from solution bags 272,274. The enhanced fluid mediais returned to reservoir 212 via return line 276. The drip rate of thechemical solutions are similarly controlled by a suitable infusion pump(not shown) as described above.

The containment means associated with pancreas preservation circuit 306comprises a generally rectangular plastic bag 490 which includes asealed body portion 492 and a preservation chamber 494. An innerzip-lock closure 366 and an outer zip-lock closure 368 are situated atthe outer perimeter of preservation chamber 494. Accordingly, theseclosures 366, 368 define a flap 370 which can be unzipped and openedwith respect to the body portion 362 for allowing the organ to beinserted and properly cannulated as described above. As shown, onecorner of flap 370 is unzipped to show its operation. Closures 366, 368are then sealed for containing the organ and defining the preservationchamber 494. Reinforcing members 384, which are formed by a heat seal,are located at the terminal ends of closures 366, 368. Two zip-lockclosures 366, 368 are provided (as opposed to one) for enhancedstructural rigidity, as well as for providing a primary seal and asecondary seal to prevent unwanted leaks of any residual fluid withinpreservation chamber 494. A particular feature of pancreas bag 490 arethe sloped portions 484 which serve to collect any residual fluid withinthe lowest portion of preservation chamber 494. A vent assembly 372 isintegrated within body portion 492 and extends below both zip lockclosures 366, 368 and into preservation chamber 494. The top vent 372includes a stopcock valve 374 which allows air to be extracted from orplaced into preservation chamber 494. Additionally, it is contemplatedthat preservation chamber 494 could be filled with a bio-compatiblefluid such as saline, or even a pharmaceutically active fluid (forcontacting or bathing the exterior of the organ) through vent 372 afterproperly sealing flap 370. Pancreas preservation bag 490 may also beprovided with one or more reinforcing ribs 376 which provide additionalstructural rigidity to the preservation bag (while being suspended) andfurther assist in maintaining a consistent shape. Additionally, a hole378 is provided within each corner of preservation bag 490 which alsoallows the bag to be suspended from a horizontal support member 380 by apair of bag hangers 382. A particular advantage of the soft shell bag490 is that ultrasound testing can be performed on the organ preservedtherein because the ultrasound probe can be placed against the organwhile being protected by the plastic wall of the bag. It should be notedthat the small intestine can be preserved in a similar fashion to thepancreas disclosed above.

With reference to FIG. 10, the preservation system 300 for preservingone or two lungs 500 is shown. The lung preservation circuit 308 is alsooperational for delivering oxygenated fluid media to the lungs 500 andcarrying depleted fluid away from the lungs 500. Lung preservationcircuit 308 also utilizes an integrated preservation device 204 as shownand described above. The warmed and oxygenated preservation fluid mediais carried from one port of oxygenator 208 to an arterial filter 314 viaoutlet line 312. An ultrasonic flow probe 316 measures the flow ratethrough line 312. Line 312 terminates at arterial stopcock connector508. A pressure transducer 510 is formed at the opposite end of stopcockconnector 508 and also connects to the arterial fitting 512 which ispreferably molded or integrated with the soft shell bag. An arterialcannula 514 is inserted within arterial fitting 512 and extends withinthe preservation chamber 534 of soft shell bag 530. An arterial cannula514 then connects to the pulmonary artery 516 which then branches toeach lung for delivering the oxygenated preservation fluid media to thelungs 500. In a similar fashion as described above, a pair of returnlines 518 extend between the top cover assembly 22 of fluid reservoir212 and a pair of stopcock connectors 520. As shown, each stopcockconnector 520 is integrally formed with soft shell bag 530, and ispositioned in fluid communication with the collection portions 522formed within preservation chamber 534. An ultrasonic flow probe 524 isdisposed along each return line 518 for monitoring the returned flow ofdepleted fluid. While not specifically shown, the pulmonary veins of thelungs 500 are not cannulated, but rather are allowed to drain directlyinto the preservation chamber 534. As specifically shown, the lowerportion of preservation chamber 534 includes an arcuate surface 526 forpromoting flow of the depleted fluid into the collection portions 522.

As with the other related embodiments, oxygenator 208 includes a secondrecirculation line 250 which delivers temperature controlled andoxygenated preservation fluid to a leukocyte filter 254 and an optionalhemodialysis filter 264. The outlet of filter 264 connects to a similartwo-port drip manifold 270 which receives the chemical solutions at thepredetermined drip rates from solution bags 272, 274. The enhancedpreservation fluid media is then returned to reservoir 212 via returnline 276. The drip rates of the chemical solutions are also controlledby a suitable infusion pump (not shown) as described above.

The containment means associated with lung preservation circuit 308 alsocomprises a generally rectangular plastic bag 530 which includes asealed body portion 532 and a preservation chamber 534. An innerzip-lock closure 366 and an outer zip-lock closure 368 are situated atthe outer perimeter of preservation chamber 534. Accordingly, theseclosures 366, 368 also define a flap 370 which can be unzipped andopened with respect to the sealed body portion 532 for allowing thelungs to be inserted and properly cannulated as described above.Closures 366, 368 are then sealed for containing the lungs and definingthe preservation chamber 534. Reinforcing members 384, which are formedby a heat seal, are located at the terminal ends of closures 366, 368.Two zip-lock closures 366, 368 are provided (as opposed to one) forenhanced structural rigidity, as well as for providing a primary sealand a secondary seal to prevent unwanted leaks of any residual fluidwithin preservation chamber 534. A pair of vent assemblies 372 areintegrated within body portion 532 and extend below both zip-lockclosures 366, 368 and into preservation chamber 534. The top of eachvent 372 includes a stopcock valve 374 which allows bi-directional fluidcommunication with preservation chamber 534. As shown, the trachea isconnected to a ventilation tube and cannula 504 which is also integrallyformed with lung preservation bag 530. A regulated volume of air isprovided to ventilation line 504 by a suitable ventilation machine 506.As the lungs must be periodically ventilated by a suitable ventilationmachine 506 to prevent collapse of the alveoli of the lung, thisnecessitates that the volume defined by preservation chamber 534 expandand contract to accommodate the corresponding expansion and contractionof lungs 500. Accordingly, opening vents 372 allows air movement in andout of preservation chamber 534. This expansion and contraction can beaccomplished through any means for respirating the lungs.

Lung preservation bag 530 may also be provided with one or morereinforcing ribs 376 which function substantially as described above.Additionally, a hole 378 is provided within each corner of preservationbag 530 which allows the bag to be suspended from a horizontal supportmember 380 by a pair of bag hangers 382. While this feature is notspecifically shown, it should be understood that bag hangers 382function as shown in FIGS. 7-9.

Turning now to FIG. 11, the portable preservation system 540 accordingto a preferred embodiment of the present invention is shown. Morespecifically, the portable preservation system 540 includes a body 542having four locking casters 544. One side of portable preservationsystem 540 includes a storage area 546 for housing the components ofpreservation circuit 202. A cover 548 is provided for protectingpreservation circuit 202 during transportation. The other side ofportable preservation system 540 includes the electronics portion 550.As shown, electronics portion 550 includes a power source 552 having abattery and uninterruptable power supply (UPS) 554 and a power converter556. As shown, the pump controller 558 is positioned next to powersource 552, and can either be the controller for centrifugal pump 232 orthe controller unit 282 for pulsatile pump 280. The heating/coolingcontrol unit 236 is preferably disposed on top of power source 552 andpump controller 558. Also shown is that water circulation lines 240extend between heat exchanger 210 and water heater/cooler unit 236.Additionally, a regulated oxygen tank 178 is secured within storage area546. The system processor/controller 560 is disposed on top of waterheater/cooler unit 236. Finally, the two-channel flowmeter 562 isintegrated into the top of electronics portion 550. Also shown is anotebook style personal computer 564 which can be secured or integratedwith the top of portable preservation system 540. The display ofpersonal computer 564 is shown as displaying the various pressure andflow signals received from system controller 560. The system controller560, also has a data logger (not shown) for digital storage of all data(flow, pressures, oxygen saturation, volume, and EKG activity) recordedduring the preservation, transportation, evaluation or resuscitationperiod.

The components within electronics portion 550 also include variousdisplays for monitoring the operation of portable preservation system540. More specifically, water heater/cooler unit 236 includes atemperature display 586. Central processor/controller 560 is shown toinclude three displays 588 for preferably displaying any of the datawhich is received and/or processed by central controller 560. Finally,flowmeter 562 is shown to include two displays 590 for presenting theflow rates of the preservation fluid media flowing through preservationcircuit 202. Also shown is that mechanical control arm 566 is operatedby and extends from system controller 560.

A particular feature of the portable preservation system 540 is thehinged arm 570, which is pivotably coupled to pivot bracket 568. A rodor pole 572 extends vertically from the outboard end of arm 570. Pole572 can have various support brackets clamped thereto. Morespecifically, clamp bracket 574 supports pump driver 232. Clamp bracket576 includes a semi-circular member 578 for supporting integratedpreservation container 204. Finally, a horizontal support member 380 ispositioned so that solution bags 272 and 274 may be suspended therefrom.

It should be particularly noted that the portable preservation system540 shown in FIG. 11 is not necessarily drawn to scale, and includes anexemplary preservation circuit 202 configured therein. Accordingly, itwill be appreciated by the skilled artisan that any of the preservationcircuits disclosed herein may be configured within storage area 546 andconnected to electronics portion 550. While not specifically shown, itshould be understood that the signals produced by pressure transducers72, 256 and flow probes 66, 68 are connected into processor/controller560 and flowmeter 562. It is also contemplated that controller 560 mayalso receive various signals from an integrated hematocrite and oxygensensor, such as that manufactured by Medtronic. Additionally, the softshell preservation bags 360, 440, 490, 530 for preserving or maintainingany solid organ may also be configured and suspended within storage area546.

It is contemplated that the electrical components contained withinportable presentation system 540 are powered by a specialized powersource 552. As disclosed, power source 552 provides universal 110/220VAC power at the appropriate 60/50 Hz level depending upon theelectronic equipment contained therein. Power source 552 is also capableof receiving 110/220 VAC power at 60/50 Hz, as well as DC power rangingfrom 12 to 24 volts via receptacles. Thus, power source 552 alsoincludes a bi-directional DC/AC power converter 556 which can acceptpower from a variety of sources which might be found in land basedvehicles, ambulances and aircraft including airplanes and helicopters.It is further contemplated that power source 552 also includes some formof stored energy device in the form of UPS 554 for delivering thenecessary level of power to the portable presentation system whenexternal power is unavailable.

Referring now to FIG. 12, the various methods associated withpreservation systems 200 and 300 are summarized. Upon reviewing thefollowing description, one skilled in the art will readily appreciatethat the steps comprising the disclosed method are supported by thevarious exemplary embodiments of the present invention. In summary, thedonor organ, such as donor heart 12 is harvested at block 600. Next, thedonor organ is connected to the preservation circuit, such aspreservation circuit 200, and also placed within the preservationcontainer 206, as shown at block 602. At block 604, the preservationfluid media of the present invention is delivered to at least one majorvessel, preferably an artery, of the donor organ. At block 606, thedepleted preservation fluid media is transported away from the donororgan. At block 608, the temperature of the fluid media and/or the donororgan are maintained at a substantially normothermic temperature ofbetween about 20° C. and about 37° C. At block 610, at least part of thepreservation fluid media is oxygenated by oxygenator 208. At block 612,the preservation fluid media is filtered as described above. At block614, the flow rate and/or pressure of the preservation fluid media canbe measured and monitored, such as by central controller 560 andflowmeter 562. At block 616, the preservation fluid media can optionallybe delivered to the exterior of the donor organ, for either bathing orproviding the chemical solutions within the fluid media to the exteriorof the organ. Finally, return line 618 represents that the preservationperiod can be continued for up to or exceeding twenty-four (24) hours byrepeating the present method and continuing the delivery of preservationfluid to a major vessel of the donor organ at block 604.

The fluid media of the present invention comprises whole blood and apreservation solution. As noted above, certain of the compositions,methods and systems/devices of the present invention employ whole bloodthat is compatible with the organ(s) being preserved. Based uponexperimental and clinical studies, it's been shown that donor or donorcompatible blood perfusate is a more suitable alternative for clinicaldonor heart preservation because it provides better substrate, oxygendelivery, endogenous-free radical scavengers, potent buffers, andimproved oncotic pressure. Whole blood that has had certain componentsor constituents removed that may have a deleterious effect in theorgan(s) being preserved over time may optionally be employed. Forexample, in one embodiment, the whole blood is treated prior to beingemployed in the present invention by having been passed through aleukocyte depleting filter, resulting in leukocyte-depleted blood. Itwill be appreciated that, since one of the goals of the presentinvention is to provide an environment that most closely approximatesthe donor, the more compatible the whole blood, the better the overallchances of successful preservation.

The whole blood is mixed with a preservation solution in order to form afluid composition (also referred to herein as fluid or fluid media). Thefluid may be formed by mixing the whole blood with the elements of thepreservation solution any time prior to delivery to the major vessel(s)selected and/or to the exterior of the organ such that the fluid orfluid media is provided to the vessels and also bathes or substantiallysurrounds the organ. The elements of the preservation solution can beadmixed with the whole blood either singly or in any combination. Forexample, in one preferred embodiment, a shelf-stable preservationsolution premix is formed by admixing a carbohydrate, sodium chloride,potassium, calcium, magnesium, bicarbonate ion, epinephrine andadenosine in advance of forming the fluid media. The final fluid mediais then formed by combining the whole blood, the premix described above,as well as other desired fluid components which are not shelf-stable insuch a premix such as insulin, just prior to delivery to the organ.

The fluids and/or the organ preservation solution of the presentinvention employ effective amounts of carbohydrates, electrolytes,hormones, and other pharmaceutically active or beneficial agents whichare conventionally available for intra-venous or direct injectiondelivery. By the term “effective amount,” as used herein, is meant anamount sufficient to provide a beneficial effect on the organ(s) beingpreserved. Without limitation, such beneficial effects includemaintaining the organ's function, organ viability, implantability,transplantability, or an increase in or improvement of any of theforegoing over time. In one highly preferred embodiment, such effectiveamounts are employed such that the organ remains sufficiently viable fortransplant 24 hours after removal from the donor; still more preferably36 hours after removal; still more preferably 48 hours after removal;and yet more preferably, 72 hours after removal.

Examples of constituents which may be employed in the fluid media and/orpreservation solution of the present invention include, withoutlimitation: carbohydrates (glucose, dextrose); electrolytes (sodium,potassium, bicarbonates, calcium, magnesium); antibiotics andantimicrobials (gram negative and gram positive, e.g., penicillin at250,000 to 1,000,000 units, preferably 250,000 units); hormones(insulin, epinephrin); endogenous metabolites or precursors ofendogenous metabolites (adenosine, L-Arginine); fatty acids (saturatedand unsaturated, short chain and long chain); and conventionalpharmaceutically-active agents (such as heparin, nitroglycerin, ACEinhibitors, beta-blockers, calcium channel blockers, cytoprotectiveagents, antioxidants, complements, anti-complements, immunosuppressiveagents, nonsteroidal anti-inflammatories, anti-fungal medications,anti-viral medications, steroids, vitamins, enzymes, co-enzymes, and thelike); and other materials conventionally employed for intravenousadministration or direct injection to assist in delivery,bioavailability, or stability of the solution. Other constituents canalso be used (as will be appreciated by the skilled artisan) thatcontrol pH, stabilize the solution, control viscosity, etc.

The following tables set forth in greater detail various constituentswhich may be used, either alone or in combination, in the fluids and/ororgan preservation solution, at one or more of the stated levels. Itshould be noted that the levels given are the preferred levels, with thelevel indicated as P=as being at least one highly preferred level.

TABLE 1 Heart Lung Kidney Liver Pancreas Carbohydrates 2.5-5% 2.5-5%2.5-5% 2.5-5% 2.5-5% P = Dextrose P = 5% P = 5% P = 5% P = 5% P = 2.5%Sodium 0.45-0.9% 0.45-0.9% 0.45-0.9% 0.45-0.9% 0.45-0.9% Chloride P =0.9% P = 0.9% P = 0.9% P = 0.9% P = 0.9% (NaCL) Potassium 4-15 meq/L4-15 meq/L 4-15 meq/L 4-15 meq/L 4-15 meq/L P = 10 meq/L P = 10 meq/L P= 20 meq/L P = 10 meq/L P = 10 meq/L Calcium 0.25-1.5 gm/L 0.25-1.5 gm/L0.25-1.5 gm/L 0.25-1.5 gm/L 0.25-1.5 gm/L P = 0.5 gm/L P = 0.5 gm/L P =0.5 gm/L P = 0.5 gm/L P = 0.5 gm/L Antibiotics gram negative gramnegative gram negative gram negative gram negative Antimicrobials⁺and/or and/or and/or and/or and/or gram positive gram positive grampositive gram positive gram positive coverage coverage coverage coveragecoverage Antifungals 1. DiFlucan 100-400 mg/L 100-400 mg/L 100-400 mg/L100-400 mg/L 100-400 mg/L (Fluconazole) P = 100 mg/L P = 100 mg/L P =100 mg/L P = 100 mg/L P = 100 mg/L 2. Amphotericin B 1-5 mg/L 1-5 mg/L1-5 mg/L 1-5 mg/L 1-5 mg/L P = 1 mg/L P = 1 mg/L P = 1 mg/L P = 1 mg/L P= 1 mg/L Insulin 20-60 U/L 20-60 U/L 20-60 U/L 20-60 U/L 20-60 U/L P =45 U/L P = 45 U/L P = 45 U/L P = 45 U/L P = 45 U/L Epinephrin 0.5-4 mg/L0.5-4 mg/L 0.5-4 mg/L 0.5-4 mg/L 0.5-4 mg/L P = 1 mg/L P = 0.5 mg/L P =1 mg/L P = 1 mg/L P = 1 mg/L Magnesium 0.5-2 gm/L 0.5-2 gm/L 0.5-2 gm/L0.5-2 gm/L 0.5-2 gm/L P = 1 gm/L P = 1 gm/L P = 1 gm/L P = 1 gm/L P = 1gm/L NaHCO₃ 10-50 meq/L 10-50 meq/L 10-50 meq/L 10-50 meq/L 10-50 meq/LP = 50 meq/L P = 50 meq/L P = 50 meq/L P = 50 meq/L P = 50 meq/LAdenosine 500 μmol/L-5 mmol/L 500 μmol/L-5 mmol/L 500 μmol/L-5 mmol/L500 μmol/L-5 mmol/L 500 μmol/L-5 mmol/L P = 2 mmoL P = 2 mmoL P = 2 mmoLP = 2 mmoL P = 2 mmoL L-Arginine 5 μmol/L-1 M/L 5 μmol/L-1 M/L 5μmol/L-1 M/L 5 μmol/L-1 M/L 5 μmol/L-1 M/L P = 0.5 m P = 1 M P = 0.5 M P= 0.5 M P = 0.5 M SPM-5185 5-50 μmoL/L 5-50 μmoL/L 5-50 μmoL/L 5-50μmoL/L 5-50 μmoL/L Organic Nodoner P = 10 μmoL P = 20 μmoL P = 10 μmoL P= 10 μmoL P = 10 μmoL Heparin Sodium 500-1500 U/L 500-1500 U/L 500-1500U/L 500-1500 U/L 500-1500 U/L P = 500 U/L P = 500 U/L P = 500 U/L P =500 U/L P = 500 U/L Nitroglycerin 50-100 mg/L 50-100 mg/L 50-100 mg/L50-100 mg/L 50-100 mg/L P = 50 mg/L P = 50 mg/L P = 25 mg/L P = 25 mg/LP = 25 mg/L ACE Inhibitors 1-20 mg/L 1-20 mg/L 1-20 mg/L 1-20 mg/L 1-20mg/L Vasotec P = 10 mg/L P = 10 mg/L P = 10 mg/L P = 10 mg/L P = 10 mg/LEnalaprilat Beta Blockers 1. Lopressor 100-450 mg/L 100-450 mg/L 100-450mg/L 100-450 mg/L 100-450 mg/L (Metoprolol P = 200 mg/L P = 200 mg/L P =200 mg/L P = 200 mg/L P = 200 mg/L Tartarate) 2. Inderal 10-100 mg/L10-100 mg/L 10-100 mg/L 10-100 mg/L 10-100 mg/L (Propanolol HCL) P = 50mg/L P = 10 mg/L P = 50 mg/L P = 50 mg/L P = 50 mg/L Ca⁺⁺ ChannelBlockers 1. Cardizem 100-400 mg/L 100-400 mg/L 100-400 mg/L 100-400 mg/L100-400 mg/L (Diltiazem HCL) P = 350 mg/L P = 350 mg/L P = 350 mg/L P =350 mg/L P = 350 mg/L 2. Cardene 30-150 mg/L 30-150 mg/L 30-150 mg/L30-150 mg/L 30-150 mg/L (Nicardipine) P = 30 mg/L P = 30 mg/L P = 30mg/L P = 30 mg/L P = 30 mg/L Prostaglandin E₁ 10-300 μg/L 10-300 μg/L10-300 μg/L 10-300 μg/L 10-300 μg/L P = 200 μg/L P = 300 μg/L P = 100μg/L P = 100 μg/L NS Lazaroids 100-500 mg/L 100-500 mg/L 100-500 mg/L100-500 mg/L 100-500 mg/L (Antioxidants) P = 300 mg/L P = 300 mg/L P =300 mg/L P = 300 mg/L P = 300 mg/L Complement Neutralizers 1. SCR₁ As apriming As a priming As a priming As a priming As a priming SolubleComplement solution not drip solution not drip solution not dripsolution not drip solution not drip Receptor Type 1 100-1000 mg/L100-1000 mg/L 100-1000 mg/L 100-1000 mg/L 100-1000 mg/L Antibodies P =250 mg/L P = 250 mg/L P = 250 mg/L P = 250 mg/L P = 250 mg/L primingfluid or priming fluid or priming fluid or priming fluid or primingfluid or effective dose effective dose effective dose effective doseeffective dose 2. AntiComplement 10-100 mg/L 10-100 mg/L 10-100 mg/L10-100 mg/L 10-100 mg/L Antibodies to C5a, P = 50 mg/L P = 50 mg/L P =50 mg/L P = 50 mg/L P = 50 mg/L C5-9, CD 18 effective dose effectivedose effective dose effective dose effective dose ProstacyclineSdumedral* As a priming As a priming As a priming As a priming As apriming Methylprednisolone solution not drip solution not drip solutionnot drip solution not drip solution not drip 125-500 mg/L 125-500 mg/L125-500 mg/L 125-500 mg/L 125-500 mg/L P = 125 mg/L P = 125 mg/L P = 125mg/L P = 125 mg/L P = 125 mg/L Mannitol* As a priming As a priming As apriming As a priming As a priming solution not drip solution not dripsolution not drip solution not drip solution not drip 12.5-50 g/L12.5-50 g/L 12.5-50 g/L 12.5-50 g/L 12.5-50 g/L P = 12.5 g/L P = 12.5g/L P = 12.5 g/L P = 12.5 g/L P = 12.5 g/L

See Tables 2A and 2B*Priming solution means that the solution is broughtto these levels and is not continuously added; it is simply replenishedif there is additional transfusing.

TABLE 2A Antimicrobials Heart Lung Kidney Liver Pancreas Flagyl 500 mg/8hrs 500 mg/8 hrs 500 mg/8 hrs 500 mg/8 hrs. 500 mg/8 hrs (Metronidazole)Boluses or Boluses or Boluses or Boluses or Boluses or 500-1000 mg/L500-1000 mg/L 500-1000 mg/L 500-1000 mg/L 500-1000 mg/L P = 1000 mg/L orED* P = 1000 mg/L or ED P = 1000 mg/L or ED P = 1000 mg/L or ED P = 1000mg/L or ED Cleocin 600-900 mg/8 hrs. 600-900 mg/8 hrs. 600-900 mg/8 hrs.600-900 mg/8 hrs. 600-900 mg/8 hrs. (Clindamycin) 600-900 mg/L 600-900mg/L 600-900 mg/L 600-900 mg/L 600-900 mg/L P = 900 mg/L or ED P = 900mg/L or ED P = 900 mg/L or ED P = 900 mg/L or ED P = 900 mg/L or EDBactrim 15-20 mg/L 15-20 mg/L 15-20 mg/L 15-20 mg/L 15-20 mg/L(Trimethoprim/ Boluses or ED Boluses or ED Boluses or ED Boluses or EDBoluses or ED Sulfamethoxazole) Vancomycin 500-1 gm/12 hrs 500-1 gm/12hrs 500-1 gm/12 hrs 500-1 gm/12 hrs 500-1 gm/12 hrs P = 500 mg/L or ED P= 500 mg/L or ED P = 500 mg/L or ED P = 500 mg/L or ED P = 500 mg/L orED *ED = effective Dose

TABLE 2B Antibiotics Heart Lung Kidney Liver Pancreas Aminoglycosides(Family) 1. Amikacin 15 mg/L Boluses 15 mg/L Boluses 15 mg/L Boluses 15mg/L Boluses 15 mg/L Boluses or ED* or ED or ED or ED or ED 2.Geutamicin ED ED ED ED ED 3. Kanamycin ED ED ED ED ED 4. Neomycinsulfate ED ED ED ED ED 5. Streptomycin ED ED ED ED ED 6. Tobramycin EDED ED ED ED Carbapanems (Theinamycins) (Family) 1. Imipenem & ED ED EDED ED Cilastatin (Primaxin) Cephalosporins: 1^(st), 2^(nd) & 3^(rd)generations (Family) 1. Cejamandole 0.5-1 gm/6-8 hrs. 0.5-1 gm/6-8 hrs.0.5-1 gm/6-8 hrs. 0.5-1 gm/6-8 hrs. 0.5-1 gm/6-8 hrs. (Mandol) BolusesBoluses Boluses Boluses Boluses P = 1 gm/L or ED P = 1 gm/L or ED P = 1gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED 2. Kefzol 1-2 gm/L 1-2 gm/L1-2 gm/L 1-2 gm/L 1-2 gm/L (Cefazolin) P = 1 gm/L or ED P = 1 or ED P =1 or ED P = 1 or ED P = 1 or ED 3. Cefobid 2-4 gm/L 2-4 gm/L 2-4 gm/L2-4 gm/L 2-4 gm/L (Cefoperazone) P = 2 gm/L or ED P = 2 gm/L or ED P = 2gm/L or ED P = 2 gm/L or ED P = 2 gm/L or ED 4. Claforan 1-2 gm/L 1-2gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Cefotaxime) P = 1 gm/L orED P = 1 gm/Lor ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED 5. Cefotetan1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Cefotan) P = 1 gm/L or EDP = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED 6.Cefoxitin 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Mefoxin) P = 1gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/Lor ED 7. Fortaz 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L(Ceftazidime) P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1gm/L or ED P = 1 gm/L or ED 8. Cefizox 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2gm/L 1-2 gm/L (Ceftizoxime) P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/Lor ED P = 1 gm/L or ED P = 1 gm/L or ED 9. Ceftriaxone 1-2 gm/L 1-2 gm/L1-2 gm/L 1-2 gm/L 1-2 gm/L (Rocephin) P = 1 gm/L or ED P = 1 gm/L or EDP = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED 10. Zinacef 1-2 gm/L1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Cefuroxime) P = 1 gm/L or ED P = 1gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED 11. Keflin1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Cephalothin) P = 1 gm/L orED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED12. Cefadyl 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L 1-2 gm/L (Cephapirin) P= 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P = 1gm/L or ED Macrolides (Family) 1. Erythromycin 1-4 gm/L 1-4 gm/L 1-4gm/L 1-4 gm/L 1-4 gm/L Gluceptate P = 1 gm or ED P = 1 gm or ED P = 1 gmor ED P = 1 gm or ED P = 1 gm or ED 2. Erythromycin 1-4 gm/L 1-4 gm/L1-4 gm/L 1-4 gm/L 1-4 gm/L lactobionate P = 1 gm or ED P = 1 gm or ED P= 1 gm or ED P = 1 gm or ED P = 1 gm or ED Monobactams (Family) 1.Azactam 1-2 gm/8 hrs. 1-2 gm/8 hrs. 1-2 gm/8 hrs. 1-2 gm/8 hrs. 1-2 gm/8hrs. (Aztreonam) P = 1 gm/L or ED P = 1 gm/L or ED P = 1 gm/L or ED P =1 gm/L or ED P = 1 gm/L or ED Penicillins (Family) 1. Unasyn 1.5-3 gm/6hrs. 1.5-3 gm/6 hrs. 1.5-3 gm/6 hrs. 1.5-3 gm/6 hrs. 1.5-3 gm/6 hrs.(Ampicillin/ P = 1.5 gm/L or ED P = 1.5 gm/L or ED P = 1.5 gm/L or ED P= 1.5 gm/L or ED P = 1.5 gm/L or ED Sulbactam) 2. Geopen 5 gm/4 hrs. orED 5 gm/4 hrs. or ED 5 gm/4 hrs. or ED 5 gm/4 hrs. or ED 5 gm/4 hrs. orED (Carbenicillin disodium) *ED = effective Dose

Because the present invention allows organs to be stored at normothermicconditions, and in a normal or near normal functioning state, thecompositions and methods of the present invention are preferablysubstantially-free of agents used in hypothermic cold storagepreservation solutions such as nonmetabilizable impermeants such aslactobionates, pentafraction, and the like.

In a preferred embodiment, the preservation solution and/or fluid mediais maintained at a pH of about 7.35 to about 8.5; more preferably about7.4 to about 7.6; and still more preferably about 7.4 to about 7.5.

The compositions, methods, and systems/devices of the present inventionare particularly useful in that they can preserve organs for significanttime periods in a normal or near-normal function state. They canaccomplish this at normothermic or substantially normothermictemperatures. As used herein, normothermic or substantially normothermicmeans a temperature range of preferably about 20° C. to about 37° C.,and still more preferably about 25° C. to about 37° C. It should benoted that normothermic outside the transplant art typically means about37° C.; however, since the organ storage art has typically employedhypothermic to mean less than 20° C., and more typically about 4° C.,the skilled artisan will appreciate that normothermic or substantiallynormothermic as applied to an organ being prepared for transplantcarries a slightly different meaning in some contexts.

In addition to the significant advantage of being able to preserveorgans in excellent condition for significantly longer time periods,another significant advantage of the present invention is that, becausethe organ is capable of being stored in a functioning condition, theorgan can be tested and assessed much more easily and completely priorto implantation. For example, the following tests can be performed onthe preserved organ, to evaluate its viability and function prior totransplant:

Heart continuous EKG monitoring to assess heart rate, rhythm and theviability of the conductance system of the organ; echocardiogram toassess wall motion, valve competence, and myocardial function (ejectionfraction EF, etc.); measurement of pressures, cardiac output andcoronary flow; metabolic assessment by calculating oxygen delivery,oxygen consumption, and oxygen demand; measure of blood chemistry(electrolytes, etc.), creatinine phosphokinase (CPK), complete bloodcount (CBC); and, assessment of myocardial function in response toinotropic agents and metabolic enhancers.

Kidney continuous measurement of urine output of the kidney; measurementof urinary excretion of sodium as a functional assessment of the kidney;measurement of the urinary osmolarity, to assess the concentrationfunction of the kidney; measurement of serum and urinary blood ureanitrogen (BUN) and creatinin; ultrasound analysis, to assess thestructural integrity of the kidney; metabolic assessment of thepreserved organ by calculating oxygen delivery, oxygen consumption, and,oxygen demand; and, measurement of blood chemistry (electrolytes, etc.),complete blood count (CBC).

Liver continuous measurement of bile production (indication of livercell viability); measurement of liver function blood test (LFTs) levels(AST, ALT, alkaline phosphates, albumin, bilirubin (direct andindirect)); measurement of fibrinogen blood level (indication of livercell ability to produce clotting factors); ultrasound analysis of theliver to assess liver parenchyma, intra- and extra-hepatic biliary tree;and, metabolic assessment of the liver by calculating oxygen delivery,oxygen consumption, and oxygen demand.

Pancreas: continuous measurement of pancreatic juice volume and chemicalanalysis; measurement of serum amylase and lipase levels to assess theviability of the pancreas; ultrasound analysis to assess structuralarchitecture and pancreatic ducts integrity, diameter, and patience;measurement of serum insulin levels and glucose to assess the endocrinefunction of the pancreas; and, metabolic assessment of the pancreas bycalculating oxygen delivery, oxygen consumption, and oxygen demand.

Small Intestine: visual inspection of peristaltic movement of the bowel,indicating viable bowel muscle and nerve conduction; visual inspectionof bowel color to assess bowel blood supply and viability; metabolicassessment by calculating oxygen delivery, oxygen consumption, andoxygen demand; and, measurement of blood chemistry (electrolytes, etc.)complete blood count (CBC).

By employing the compositions, methods and systems devices of thepresent invention, the organ can also be removed and treated in thefunctioning state. For example, cytotoxic therapeutic agents such asantineoplastic agents or vectors could be delivered to the organ in anisolated fashion. In addition, other therapeutic protocols, appreciatedby those skilled in the art, e.g., gene therapy, may be applied to theorgan, prior to implantation. In addition, a harvested cadaveric organmay be resuscitated (usually within 10 to 60 minutes of death), and theviability of the organ analyzed, e.g., by the above-described methods.

The foregoing discussion discloses and describes exemplary embodimentsof the present invention. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the invention as definedin the following claims.

1. A method for perfusing a heart, comprising placing the heart in anex-vivo apparatus, perfusing the heart with a fluid to cause the heartfunction in a viable state, and maintaining the heart at a physiologictemperature during perfusion.
 2. The method of claim 1, includingcontrolling perfusion pressure.
 3. The method of claim 1, includingtherapeutically treating the heart.
 4. The method of claim 1, includingcontrolling flow rate of the perfusion fluid.
 5. The method of claim 1,including oxygenating the fluid.
 6. The method of claim 1, includingpumping the fluid in pulsatile fashion.
 7. The method of claim 1,including transporting the heart from a first location to a secondlocation remote from the first location.
 8. The method of claim 1,including diagnosing a condition of the heart.
 9. The method of claim 1,including maintaining the heart for more than about 6 hours.
 10. Themethod of claim 1, including maintaining the heart for more than about24 hours.
 11. A method for evaluating a heart for a transplant,comprising placing the heart in an ex-vivo apparatus, perfusing theheart to cause it to function in a viable state, maintaining the heartat a physiologic temperature during perfusion, and performing one ormore tests on the heart during perfusion.
 12. The method of claim 11,including performing an echocardiogram on the heart during perfusion.13. The method of claim 11, including performing a metabolic assessmenton the heart during perfusion.
 14. The method of claim 11, includingmeasuring pH of fluid perfusing through the heart.
 15. A method fortreating a heart, comprising placing the heart in an ex-vivo apparatus,perfusing the heart to cause it to function in a viable state,maintaining the heart at a physiologic temperature during perfusion, andapplying a treatment to the heart during perfusion.
 16. The method ofclaim 15, including applying a direct current shock to the heart tocorrect arrhythmia.
 17. The method of claim 16, including performingsurgery on the heart.